jsil_parsert: construct with message handler

[tautschnig]

This both avoids an object of static lifetime as well as it fixes the (transitive) use of the deprecated messaget() constructor.

• Each commit message has a non-empty body, explaining why the change was made.
• Methods or procedures I have added are documented, following the guidelines provided in CODING_STANDARD.md.
• n/a The feature or user visible behaviour I have added or modified has been documented in the User Guide in doc/cprover-manual/
• Regression or unit tests are included, or existing tests cover the modified code (in this case I have detailed which ones those are in the commit message).
• n/a My commit message includes data points confirming performance improvements (if claimed).
• My PR is restricted to a single feature or bugfix.
• n/a White-space or formatting changes outside the feature-related changed lines are in commits of their own.

[codecov]

Codecov Report

Attention: 21 lines in your changes are missing coverage. Please review.

Comparison is base (1068770) 79.08% compared to head (c49b489) 79.08%.
Report is 2 commits behind head on develop.

Files	Patch %	Lines
src/jsil/parser.y	0.00%	6 Missing ⚠️
src/jsil/scanner.l	0.00%	5 Missing ⚠️
src/jsil/jsil_parser.h	0.00%	4 Missing ⚠️
src/util/parser.h	0.00%	4 Missing ⚠️
src/jsil/jsil_language.cpp	0.00%	2 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #8136      +/-   ##
===========================================
- Coverage    79.08%   79.08%   -0.01%     
===========================================
  Files         1696     1695       -1     
  Lines       196505   196514       +9     
===========================================
  Hits        155408   155408              
- Misses       41097    41106       +9     

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