nirfsg- Fix ErrorMessage API

[rahur-NI]

• This contribution adheres to CONTRIBUTING.md.
• I've updated CHANGELOG.md if applicable.
• I've added tests applicable for this pull request

What does this Pull Request accomplish?

This PR fixes error_message method in nifrsg. The ErrorMessage parameter was passed as an input parameter, but the niRFSG_ErrorMessage C API returns the error string.
Changes:

• Changed errorMessage parameter direction from 'in' to 'out' in nirfsg metadata.

List issues fixed by this Pull Request below, if any.

What testing has been done?

• A successful tox execution and the changes in the generated files are with respect to the parameter errorMessage treated as an output parameter instead of input parameter.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 33.33333% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.85%. Comparing base (f77dd57) to head (6e4959a).
⚠️ Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
generated/nirfsg/nirfsg/_grpc_stub_interpreter.py	33.33%	2 Missing ⚠️
generated/nirfsg/nirfsg/_library_interpreter.py	33.33%	2 Missing ⚠️
generated/nirfsg/nirfsg/session.py	33.33%	2 Missing ⚠️

❌ Your patch status has failed because the patch coverage (33.33%) is below the target coverage (70.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2174      +/-   ##
==========================================
- Coverage   91.18%   89.85%   -1.33%     
==========================================
  Files          67       73       +6     
  Lines       16489    19006    +2517     
==========================================
+ Hits        15035    17078    +2043     
- Misses       1454     1928     +474     

Flag	Coverage Δ
codegenunittests	84.90% <ø> (ø)
nidcpowersystemtests	94.65% <ø> (+0.04%)	⬆️
nidcpowerunittests	89.53% <ø> (ø)
nidigitalsystemtests	92.26% <ø> (ø)
nidigitalunittests	68.44% <ø> (ø)
nidmmsystemtests	92.72% <ø> (ø)
nifakeunittests	86.01% <ø> (ø)
nifgensystemtests	94.61% <ø> (ø)
nimodinstsystemtests	73.85% <ø> (ø)
nimodinstunittests	94.20% <ø> (ø)
nirfsgsystemtests	81.12% <33.33%> (?)
niscopesystemtests	92.94% <ø> (ø)
niscopeunittests	43.20% <ø> (ø)
nisesystemtests	91.50% <ø> (ø)
niswitchsystemtests	82.03% <ø> (ø)
nitclksystemtests	94.87% <ø> (ø)
nitclkunittests	98.26% <ø> (ø)

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

Files with missing lines	Coverage Δ
generated/nirfsg/nirfsg/_grpc_stub_interpreter.py	78.32% <33.33%> (ø)
generated/nirfsg/nirfsg/_library_interpreter.py	74.14% <33.33%> (ø)
generated/nirfsg/nirfsg/session.py	90.01% <33.33%> (ø)

... and 4 files with indirect coverage changes

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update f77dd57...6e4959a. Read the comment docs.

🚀 New features to boost your workflow:

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

[ni-jfitzger]

I'm not going to tell you to remove this function, since we spent enough time going over the API already and we ship this in at least a couple of other APIs, but I honestly have no idea what purpose it serves in our Python API. We already handle errors for the user with get_error().

@marcoskirsch do you know why we included this in other APIs?