[CONTRACTS] Allow loop contracts annotated to goto statement

[qinheping]

This PR enable loop contracts annotated to goto statement, which is we we do in Kani generated GOTO program.

• 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.
• 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).
• My commit message includes data points confirming performance improvements (if claimed).
• My PR is restricted to a single feature or bugfix.
• White-space or formatting changes outside the feature-related changed lines are in commits of their own.

[tautschnig]

Nobody reads warnings. Can you describe the scenario where side effects would be ok?

[qinheping]

According to the offline discussion. I will move all the checks and throw to contracts component. They should not be in the converter.

[codecov]

Codecov Report

Attention: Patch coverage is 58.82353% with 7 lines in your changes missing coverage. Please review.

Project coverage is 77.49%. Comparing base (f18b509) to head (7de1747).
Report is 32 commits behind head on develop.

Files	Patch %	Lines
src/ansi-c/goto-conversion/goto_convert.cpp	58.82%	7 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #8281      +/-   ##
===========================================
- Coverage    77.55%   77.49%   -0.07%     
===========================================
  Files         1721     1721              
  Lines       190128   190281     +153     
  Branches     18438    18371      -67     
===========================================
+ Hits        147448   147450       +2     
- Misses       42680    42831     +151     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.