Transfer log events as JSON objects and allow filtering on front-end (#10522)

* Return log events as JSON objects from API; render on front-end

Site UUID added to log events.

* Remove superfluous memoization of site UUID retrieval

Settings are already cached.

* Transfer timestamps in ISO-8601 format

* Move `metabase.metabot.instance/local-process-uuid` to `metabase.public-settings`

* Use `local-process-uuid` in stead of `site-uuid`

`site-uuid` is not unique across processes, which is what we want to
associate with log events.

* Remove unused import

* Allow log events to be filtered by process UUID on front-end

* Move process selector out of loading wrapper

Otherwise, if there are process UUIDs with no log events, the selector is
removed with the log event list.

* Figured out how to add docs to `defonce`

* Fix ns declaration

* Linter appeasement

* Merge log events received from back-end with previously received ones

This allows responses from multiple back-end instances to be spliced
together.

* Use MB components in stead of plain, styled HTML tags

The select is only displayed if more than one process UUID was found.

* Linter appeasement

* Move `metabase.public-settings/local-process-uuid` to `metabase.config`

* Fix sorting on multiple log event fields

* Flatten `Select` children to allow nested arrays of children

* Generate options directly under parent Select

* Limit the number of log events that we render

* Docstring and style updates

* Update editor config with Clojure files max line length

* Ensure that `NumericWrapper` is imported before use

* Cleanup layout