Investigate [and fix?] plugin version checking

[joshdover]

@cjcenizal noticed that many 1st party new platform plugins specify "8.0.0" as their version, even in the 7.x branch.

This points to the possibility that we're not doing any version checks on Platform plugins which is a problem for 3rd party plugins.

We should investigate what version checking we are doing, if there is none, add version checking that mirror what we do in legacy, and finally, update all 1st party plugins to work correctly with the new version checking.

[elasticmachine]

Pinging @elastic/kibana-platform (Team:Platform)

[cjcenizal]

Is there ever a scenario in which version-checking first-party plugins can catch a problem? If not, then perhaps we can allow Kibana maintainers to leave the version field out, and add something to our tooling to handle this intelligently (e.g. automatically generate it from the package.json or simply ignore it).

The reason I suggest this is that it just seems like a hassle for a first-party maintainer to maintain versions (e.g. bumping them) if there's no practical benefit.

[mshustov]

+1 to remove this requirement for first-party plugins. We need to finish work started in #34660

[stacey-gammon]

So, if I'm following correctly, this is how it works today:

version - A required field that is the version of your plugin. If kibanaVersion is specified, this field is ignored. If kibanaVersion is not specified, this has to match the version of Kibana or ci will fail.

kibanaVersion - An optional field that specified the version of Kibana this plugin works against. If you set this to kibana instead of an actual version number, then this field and the version field will be ignored. If you leave this field blank, ci checks will require version to be the current version of Kibana.

And how we want it to work:

version - An optional field that is the version of your plugin.

kibanaVersion - An optional field that specified the version of Kibana this plugin works against.

So, am I right in thinking that the goal is to have plugins put whatever they want inside version and not require it match the Kibana version? The plan is to stop falling back to verifying version if kibanaVersion is not defined?

[pgayvallet]

With the new plugin manifest format, internal plugins no longer have a version field, so I'll go ahead and close this.