Update deprecated fields

[PassiveModding]

This addresses the following change to jetstream which deprecates the type fields. As of today the fields are no longer present on the events

bluesky-social/jetstream#7

This change updates the event struct to be more human-readable now that we support compression and don't need to save characters as greedily.

Motivation behind this change is to make the event stream readable for someone without having to go lookup docs on event structure. Some existing fields have been a bit cryptic with naming and with value abbreviations, making the stream less understandable to new developers.

Deprecated fields:

* `event.type` -> `event.kind`
  
  * `com, id, acc` -> `commit, identity, account`

* `commit.type` -> `commit.operation`
  
  * `c, u, d` -> `create, update, delete`

To support backwards compatibility for a brief window, the old fields and values will still be emitted during a migration window.

bluesky-social/jetstream#13

[drasticactions]

LGTM, thanks!