Adding NO_WRITE ASG

[KaushikMalapati]

Description

Adding a new access security group that only allows reading, to be used with RBV pvs generated by pytmc

Motivation and Context

https://jira.slac.stanford.edu/browse/ECS-5005
pytmc PR that adds ASG field to rbv pvs: pcdshub/pytmc#328

How Has This Been Tested?

Not yet tested

Where Has This Been Documented?

Pre-merge checklist

• Code works interactively
• Code contains descriptive docstrings, including context and API

[ZLLentz]

This pair of PRs seems like a great, straight-to-the-point approach for fixing the issue. I'm curious to see it in action.

[ZLLentz]

Tiny thoughts on this side of the PR pair:

• The Makefile on this side has a version check for pytmc but the newer IOC build won't necessarily "fail" if you run an older pytmc on it. Is it still work worth updating the minimum pytmc version?

  ioc-common-ads-ioc/iocBoot/templates/Makefile.base

  Line 80 in 37e7121

  @$(PYTHON) -c "import sys, pytmc, distutils.version; print('* Found pytmc v', pytmc.__version__); sys.exit(not (distutils.version.LooseVersion(str(pytmc.__version__)) >= distutils.version.LooseVersion('$(PYTMC_MIN_VERSION)')))" || (echo "A newer pytmc is required: >= $(PYTMC_MIN_VERSION)" 2> /dev/null && exit 1)

  ,

  ioc-common-ads-ioc/iocBoot/templates/Makefile.base

  Line 28 in 37e7121

  PYTMC_MIN_VERSION ?= 2.14.0

[KaushikMalapati]

Tiny thoughts on this side of the PR pair:

• The Makefile on this side has a version check for pytmc but the newer IOC build won't necessarily "fail" if you run an older pytmc on it. Is it still work updating the minimum pytmc version?

  ioc-common-ads-ioc/iocBoot/templates/Makefile.base

  Line 80 in 37e7121

  @$(PYTHON) -c "import sys, pytmc, distutils.version; print('* Found pytmc v', pytmc.__version__); sys.exit(not (distutils.version.LooseVersion(str(pytmc.__version__)) >= distutils.version.LooseVersion('$(PYTMC_MIN_VERSION)')))" || (echo "A newer pytmc is required: >= $(PYTMC_MIN_VERSION)" 2> /dev/null && exit 1)

  
  ,

  ioc-common-ads-ioc/iocBoot/templates/Makefile.base

  Line 28 in 37e7121

  PYTMC_MIN_VERSION ?= 2.14.0

If you use an older version of pytmc, the additional access group won't affect anything, but I still think it's worth updating.

[ZLLentz]

I have no objections here.
To test this in full I need to get the pytmc tag fully deployed but we'll revisit in a follow-up if there are unforeseen issues.
I'd like to bundle this with https://jira.slac.stanford.edu/browse/ECS-5884 and do some testing so I won't tag right away