Fix a Leak in Synonym - [MOD-6490]

[GuyAv46]

Describe the changes in the pull request

1. Allocate newId after checking if the term-id pair already exists (and only if not)
2. Fix the TermData_IdExists comparison function

This bug could cause a performance hit (searching for a word from a synonym group will yield a union of the same group multiple times)

Main objects this PR modified

1. synonym map

Mark if applicable

• This PR introduces API changes
• This PR introduces serialization changes

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (f398bb5) 84.37% compared to head (8980a04) 84.37%.
Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #4355   +/-   ##
=======================================
  Coverage   84.37%   84.37%           
=======================================
  Files         192      192           
  Lines       33451    33451           
=======================================
  Hits        28223    28223           
  Misses       5228     5228           

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[github-actions]

Backport failed for 2.8, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally and resolve any conflicts.

git fetch origin 2.8
git worktree add -d .worktree/backport-4355-to-2.8 origin/2.8
cd .worktree/backport-4355-to-2.8
git switch --create backport-4355-to-2.8
git cherry-pick -x 3706035e27d7c609351899ea6be7746887f053a8 29f63b8df93f4106c08ad8139f4fb9af9a4f80fc 8980a04c2bb7570cc8feba739ac166ecd0ec2302

[github-actions]

Backport failed for 2.6, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally and resolve any conflicts.

git fetch origin 2.6
git worktree add -d .worktree/backport-4355-to-2.6 origin/2.6
cd .worktree/backport-4355-to-2.6
git switch --create backport-4355-to-2.6
git cherry-pick -x 3706035e27d7c609351899ea6be7746887f053a8 29f63b8df93f4106c08ad8139f4fb9af9a4f80fc 8980a04c2bb7570cc8feba739ac166ecd0ec2302