tr: cleanup hook logs

[Docs] Make clear Nomad requires leases in Vault for rendering certificates using the template stanza

UI: Improved stats charts

UI: Add some simple accessibility labels for line charts

UI: Use stats trackers for resource rows

Do not use cty in drivers

drivers/exec: add exec implementation

UI: Make the global logo link to the jobs page (home page)

AllocRunner v2 Feature Branch PR

was causing typed nil interface panics and served no purpose

Was mock_driver before plugins, so keep the name.

from #4777 comments

Do not register mock_driver on release builds.

PR #4392 was merged to master *after* allocrunnerv2 was branched, so the
client-specific portions must be ported from master to arv2.

Now passing the TaskDir struct to prestart hooks instead of just the
root task dir itself as dispatch needs local/.