remove GoodFramesWaiter and GoodFramesNormalizer, alias them to period equivalents

[rerpha]

Description of work

remove GoodFramesWaiter and GoodFramesNormalizer, alias them to period equivalents. Technically this is only minor as we're keeping backwards compatibility with the aliases.

A DAE using GoodFramesWaiter or GoodFramesNormalizer will now publish the period_good_frames signal in the emitted documents, rather than good_frames.

Ticket

closes #136

Acceptance criteria

Not much to test here, anywhere using GoodFramesWaiter and GoodFramesNormalizer should still work due to the alias so we won't need to fix any imports.

Documentation

Updated to reflect.

[Tom-Willemsen]

I think it's technically not quite backwards compatible as it publishes a different interesting signal - will put this in release notes, but don't think it should block the PR.