fix(SyntheticTimeSeries): synthetic time series query fails when variable contains certain characters

[MortGron]

Description

By mistake, synthetic time series queries will fail when re.escape(var) != var for some variable var in a query expression before variable replacement. However, they do not fail when variables contain characters like \.

Even though this fixes a bug, a long term solution to make variable names safer is #2762

Checklist:

• Tests added/updated.
• Documentation updated. Documentation is generated from docstrings - these must be updated according to your change.
  If a new method has been added it should be referenced in cognite.rst in order to generate docs based on its docstring.
• The PR title follows the Conventional Commit spec.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.82%. Comparing base (60b6c36) to head (7a00f08).
⚠️ Report is 5 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2766      +/-   ##
==========================================
+ Coverage   93.77%   93.82%   +0.04%     
==========================================
  Files         513      513              
  Lines       52445    52620     +175     
==========================================
+ Hits        49181    49369     +188     
+ Misses       3264     3251      -13     

Files with missing lines	Coverage Δ
cognite/client/_api/synthetic_time_series.py	95.96% <100.00%> (ø)
cognite/client/_sync_api/synthetic_time_series.py	100.00% <ø> (ø)
.../tests_unit/test_api/test_synthetic_time_series.py	97.60% <100.00%> (ø)

... and 18 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.