feat(web-console): WAL Metrics for tables

[insmac]

This PR implements the concept of metrics in the Web Console - in the first iteration WAL-related table data is available for visualization.

To create a new metric dashboard, click on the Add metrics button in the Tables action bar:

Note: Metrics have a different tab color (inactive and selected) than SQL editor ones.

Next, select an available metric widget:

The three metrics that are available in the first iteration are related to a given WAL table, and therefore a table selector will open upon adding. Non-WAL tables which we can't pull data from are grayed out.

Once you define a data source for each widget they immediately start showing data. Metrics are auto refreshed every 30 seconds (provided that the auto refresh feature is enabled in Tables action bar in the left top corner of the screen) and immediately upon bringing the tab back in focus.

Side changes:

QuestDB client has been abstracted out into two pieces: types and the actual code, to improve readability - commit 1026dcc