Improve pmac DB templates for tidier PVI engineering screen generation

[gilesknap]

Intro

During a discussion on #140 with @coretl and @shihab-dls we decided on the following to improve PVI auto screen generation for pmac.

Simplified Templates

• Create a new pmacAxis.template that incorporates:
  • all things included by dls_pmac_asyn_motor.template (cs and non-cs flavours)
  • PLUS axisStatus.template
  • i.e. ALL the per-axis things
• And a new pmacController.template (name to be decided) that includes
  • All the templates we currently instantiate per Controller
  • EXCEPT axisStatus * n
  • i.e. ALL the per-Controller things (one of each)
• Now we can make PVI devices for each of the above and have:
  • N Axis screens, 1 for each axis including all of the names:
    • $(P):AXIS$(ADDR) for axis status stuff
    • $(P):$(M): for motor record and supporting records
    • $(P):M$(ADDR) as an alias to the above

Alternative

Writing this up it occurs to me that we could instead:-

• remove references to pmacAxis.template when rendering controller templates
• insert an include of pmacAxis.template into dls_pmac_asyn_motor.template (and CS equivalent)

This would be backwards compatible because the set of PVs created would be the same (except that non-existent axes would not get axisStatus - same as the above)
@coretl do you prefer this?

[gilesknap]

after a conversation with @coretl we decided on the Alternative above.

• black is dodal
• red ticks is where the primary PV is
• aliases are used for backward compatible PVs in both the pmacController and DCM namespaces