feature(argus): Custom Views

[k0machi]

This commit adds a new way to present tests inside argus - Views. Built by users, they allow scoping tests, issues and statistics into a more focused view. The View Manager allows users to build view from existing tests, groups and releases, along with a new widget builder allowing users to select what their view should contain widget wise (Currently contains 3 widgets, copying the release dashboard structure). Additionally, the Issue View was improved to allow filtering by issue state and labels, as well as caching issue state to prevent extraneous fetches.

Fixes https://github.com/scylladb/argus/issues/352

[k0machi]

Picture demos:

• View Editor (currently only available to admins)

• View overview page

• View page itself

• Improved issue view

[soyacz]

what's the difference between 'view name' and 'display name for users'? Can we merge them?

[k0machi]

@soyacz good idea and yes, I forgot to implement that: