detect/var: Restrict var usage to single buffer

[jlucovsky]

Continuation of #13509

Issue: 1412

Extend the checks added for 7549 to include buffers.

Only consider sig matches with compatible ids/lists.

Link to ticket: https://redmine.openinfosecfoundation.org/issues/1412

Describe changes:

• Extend buffer/variable checks to buffers init data

Updates:

• Include behavioral change note (see detect/var: Restrict var usage to single buffer #13465) in upgrade notes.
• Doc format fixup (see detect/var: Restrict var usage to single buffer #13509 CI failures)
• s-v rebase

Provide values to any of the below to override the defaults.

• To use a Suricata-Verify or Suricata-Update pull request,
  link to the pull request in the respective _BRANCH variable.
• Leave unused overrides blank or remove.

SV_REPO=
SV_BRANCH=OISF/suricata-verify#2576
SU_REPO=
SU_BRANCH=

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 83.49%. Comparing base (495a12f) to head (64f92dc).
Report is 43 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #13516   +/-   ##
=======================================
  Coverage   83.48%   83.49%           
=======================================
  Files        1011     1011           
  Lines      274902   274908    +6     
=======================================
+ Hits       229507   229523   +16     
+ Misses      45395    45385   -10     

Flag	Coverage Δ
fuzzcorpus	61.78% <100.00%> (+0.01%)	⬆️
livemode	18.95% <0.00%> (-0.01%)	⬇️
pcap	44.64% <52.17%> (-0.03%)	⬇️
suricata-verify	65.03% <100.00%> (+<0.01%)	⬆️
unittests	59.14% <60.86%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[suricata-qa]

Information: QA ran without warnings.

Pipeline = 26586

[catenacyber]

I think we need to think about the expected behavior here (see SV test comment)

[catenacyber]

As discussed : needs

• a warning
• error when in "strict" mode

[jlucovsky]

Continued in #13564