Fix variable scenario filtering, and availability TS multiplier

[ktehranchi]

Fixes:

• Fixes scenario filtering of variables by Band ID. We could potentially apply this filter to other Enum classes, but I didn't want to unnecessarily filter out data unless we knew that behavior was needed:
  

  R2X/src/r2x/parser/plexos.py

  Lines 1249 to 1258 in ebac92c

  	# Filtering Variables to select only the correct band-id which should be used
  	# when accessing Variable data. We may also need to apply this filtering to
  	# other Enum classes.
  	variables = data.filter(pl.col("child_class_name") == ClassEnum.Variable.name)
  	variables = variables.group_by("object_id", maintain_order=True).map_groups(
  	lambda groupdf: groupdf.filter(pl.col("band") == pl.col("band").min())
  	)
  	data = data.filter(pl.col("child_class_name") != ClassEnum.Variable.name)
  	data = pl.concat([data, variables])

• One of the paths for parsing TS data was missing a * record['available']

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 81.12%. Comparing base (f926bb4) to head (376f77d).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #91      +/-   ##
==========================================
+ Coverage   78.49%   81.12%   +2.63%     
==========================================
  Files          40       40              
  Lines        4078     4143      +65     
==========================================
+ Hits         3201     3361     +160     
+ Misses        877      782      -95     

Files with missing lines	Coverage Δ
src/r2x/api.py	82.22% <100.00%> (ø)
src/r2x/exporter/sienna.py	94.97% <100.00%> (+0.05%)	⬆️
src/r2x/parser/plexos.py	64.00% <100.00%> (+10.27%)	⬆️

... and 5 files with indirect coverage changes

[JensZack]

This looks good to me, but we should probably add a test to cover this case. Do we have a dataset we can run that hits these changes?

[ktehranchi]

So we don't have a database that covers this test case. I don't have access to plexos to make one. One idea would be to use a more complicated public file like the caiso's deterministic plexos file as a test case. But r2x fails to convert this atm.

[pesap]

LGTM! Do you want to go ahead and merge the other branch before merging to main?