* materialize PublicChannels table
Introduce triggers for each supported database that automatically maintain a subset of the Channels table corresponding to only public channels. This improves corresponding queries that no longer need to filter out 99% DM channels.
This initial commit modifies the channel store directly for easier code reviewing, but the next wraps an experimental version around it to enable a kill switch in case there are unforeseen performance regressions.
This addresses [MM-11886](https://mattermost.atlassian.net/browse/MM-11886) and [MM-11945](https://mattermost.atlassian.net/browse/MM-11945).
* extract the experimental public channels materialization
Wrap the original channel store with an experimental version that
leverages the materialized public channels, but can be disabled to
fallback to the original implementation.
This addresses MM-11947.
* s/ExperimentalPublicChannelsMaterialization/EnablePublicChannelsMaterialization/
* simplify error handling
* move experimental config listener until after store is initialized
* Implementing structured logging
* Changes to en.json to allow refactor to run.
* Fixing global logger
* Structured logger initalization.
* Add caller.
* Do some log redirection.
* Auto refactor
* Cleaning up l4g reference and removing dependancy.
* Removing junk.
* Copyright headers.
* Fixing tests
* Revert "Changes to en.json to allow refactor to run."
This reverts commit fd8249e99bcad0231e6ea65cd77c32aae9a54026.
* Fixing some auto refactor strangeness and typo.
* Making keys more human readable.
