[INSTRM-557] add motors focus command and keyword

Blocks — Thu, 21 Apr 2022 23:33:32 +0000

When the detector will be focused, we will end up with 3 motor positions that will become their nominal positions.

I suspect we'll store those positions somewhere (ics_config?) .

Adding a few functionalities would be useful:

xcu motors move focus command to go straight to that positions
xcu motors fullInit (fullInit is certaintly not the correct denomination), What I imply by that is doing an initCcd, homeCcd and move focus in one command
motors focus keyword, that describe if the current position is nominal or not : Key('motorsPosition', Enum('focus', 'undef')

PFS-JIRA