MM-58438: simplify settings

[lieut-data]

Summary

We're simplifying the plugin configuration to focus users towards the GA functionality for v10:

• Remove the untested enabledTeams setting altogether
• Remove syncReactions and always sync reactions (as appropriate)
• Remove syncFileAttachments and always sync file attachments (as appropriate)
• Consolidate syncDirectMessages and syncGroupMessages under a new experimentalSyncChat
• Rename selectiveSync as experimentalSelectiveSync
• • Rename certificatepublic as experimentalcertificatepublic and certificatekey as experimentalcertificatekey.
• Rename disableSyncMsg as experimentalUseSharedChannels so that it defaults off.
• Rename disableCheckCredentials as internalDisableCheckCredentials
• Remove all internal and experimental options from plugin.json to hide them from the system console.

Ticket Link

Fixes: https://mattermost.atlassian.net/browse/MM-58438

[lieut-data]

LGTM, I'm hesitant to say it's a good idea to re-merge DM and GM tho, I think our DM experience at this point is better than experimental but our GMs are not really at the same level.

I agree that GMs introduce the most experimental level of functionality, but the overhead to enable one without the other is non-trivial. Syncing with @esethna, we're aiming to deprioritize chat sync altogether, with no plan to "sell" only DMs to any customer.

[JulienTant]

I agree that GMs introduce the most experimental level of functionality, but the overhead to enable one without the other is non-trivial. Syncing with @esethna, we're aiming to deprioritize chat sync altogether, with no plan to "sell" only DMs to any customer.

Sounds good then! Thanks!