Hermes: replace default JSON with human-readable output

[adizere]

Closes: #805

Many thanks @romac for code snippets & helping with navigating the code around abscissa!

Description

Primary change in this PR:

• Introduced the -j/--json flag to enable output in JSON format:

     Running `target/debug/hermes -j query channel end ibc-0 transfer channel-0`
{"timestamp":"Apr 07 21:48:04.410","level":"INFO","fields":{"message":"Using default configuration from: '.hermes/config.toml'"},"target":"ibc_relayer_cli::commands"}
{"timestamp":"Apr 07 21:48:04.415","level":"INFO","fields":{"message":"Options QueryChannelEndCmd { chain_id: ChainId { id: \"ibc-0\", version: 0 }, port_id: PortId(\"transfer\"), channel_id: ChannelId(\"channel-0\"), height: None }"},"target":"ibc_relayer_cli::commands::query::channel"}
{"status":"success","result":{"connection_hops":["connection-0"],"ordering":"Unordered","remote":{"channel_id":"channel-0","port_id":"transfer"},"state":"Open","version":"ics20-1"}}

versus pretty-printing (the default):

    Running `target/debug/hermes query channel end ibc-0 transfer channel-0`
Apr 07 21:48:31.510  INFO ibc_relayer_cli::commands: Using default configuration from: '.hermes/config.toml'
Apr 07 21:48:31.514  INFO ibc_relayer_cli::commands::query::channel: Options QueryChannelEndCmd { chain_id: ChainId { id: "ibc-0", version: 0 }, port_id: PortId("transfer"), channel_id: ChannelId("channel-0"), height: None }
Success
{
  "connection_hops": [
    "connection-0"
  ],
  "ordering": "Unordered",
  "remote": {
    "channel_id": "channel-0",
    "port_id": "transfer"
  },
  "state": "Open",
  "version": "ics20-1"
}

Notable code changes in this PR:

• override the default abscissa::EntryPoint with out custom EntryPoint in relayer-cli/src/entry.rs per suggestion;
  • this allowed us to introduce the global application flag -j or --json to enable JSON only output (default is pretty printing)
  • also allowed us to remove the global -v verbose parameter
• introduced the json() method in conclude.rs to peek into the application state and infer if JSON output should be on or off
• we can dispense with relayer-cli/build.rs
  • this was a workaround introduced in Help and usage show wrong executable name 'ibc-relayer-cli`  #590
  • the purpose was to ensure that Hermes CLI output shows hermes (the binary name) instead of ibc-relayer-cli (the crate name)

---

For contributor use:

• Updated the Unreleased section of CHANGELOG.md with the issue.
• If applicable: Unit tests written, added test to CI.
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Updated relevant documentation (docs/) and code comments.
• Re-reviewed Files changed in the Github PR explorer.

[romac]

imho whether or not we output JSON should be a global command-line flag (available on every commands) rather than a config option, otherwise if one wants to use the CLI programmatically (either in a script or in the e2e test suite) one has to ensure that the config file contains the proper value for log_json.

I wonder if we could do this by defining our own [Entrypoint struct](https://docs.rs/abscissa_core/0.5.2/src/abscissa_core/command/entrypoint.rs.html#11-33, adding the option there, and telling the framework about it?

What do you think?

[romac]

👍

[codecov-io]

Codecov Report

Merging #796 (2e2dc0b) into master (b1b37f5) will increase coverage by 31.3%.
The diff coverage is n/a.

❗ Current head 2e2dc0b differs from pull request most recent head 573a5a9. Consider uploading reports for the commit 573a5a9 to get more accurate results

@@            Coverage Diff            @@
##           master    #796      +/-   ##
=========================================
+ Coverage    13.6%   45.0%   +31.3%     
=========================================
  Files          69     165      +96     
  Lines        3752   11309    +7557     
  Branches     1374       0    -1374     
=========================================
+ Hits          513    5090    +4577     
- Misses       2618    6219    +3601     
+ Partials      621       0     -621     

Impacted Files	Coverage Δ
...application/ics20_fungible_token_transfer/error.rs	0.0% <ø> (ø)
...ion/ics20_fungible_token_transfer/msgs/transfer.rs	22.2% <ø> (ø)
..._transfer/relay_application_logic/send_transfer.rs	85.7% <ø> (ø)
modules/src/events.rs	0.0% <ø> (ø)
modules/src/handler.rs	100.0% <ø> (ø)
modules/src/ics02_client/client_consensus.rs	55.8% <ø> (ø)
modules/src/ics02_client/client_def.rs	32.3% <ø> (ø)
modules/src/ics02_client/client_state.rs	65.1% <ø> (ø)
modules/src/ics02_client/client_type.rs	79.1% <ø> (+31.5%)	⬆️
modules/src/ics02_client/context.rs	90.4% <ø> (ø)
... and 266 more

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[romac]

Looks great, thanks @adizere!

One last thing I wonder now that I am looking at an example: in the human-readable case (ie. when --json is not supplied), how about using the standard dbg!/Debug output instead of still outputting JSON? Since is the output meant to be human-readable, I find the Debug output to be more readable than JSON.

Just a thought, based on a personal preference. What do you think?

[cezarad]

The result of command and raw txs is different: E.g., create channel will print "Channel handshake finished for Channel{ ... } " in a different style than the "Success" message.

[adizere]

Status of this PR as of commit a35a225:

• the last commit enforces filtering by modules, so that only log from crates ibc_relayer and ibc_relayer_cli are now printed
• with this, we can use debug! or trace! to print lower-level tracing information (without being overwhelmed by tendermint or hyper debug lines)
• this filter is enabled both for JSON output and pretty-printing

The feature of having debug and trace logging appeared to be useful in debugging recent work (#747).