core: make ContractDefinitionService find definition by its id

[ndr-brt]

What this PR changes/adds

ContractDefinitionService is currently getting all the definitions and then filter them in memory, this PR makes it use the ContractDefinitionStore.findById method directly

Why it does that

Improve performances

Further notes

Linked Issue(s)

Closes #1172

Checklist

• added appropriate tests?
• performed checkstyle check locally?
• added/updated copyright headers?
• documented public classes/methods?
• added/updated relevant documentation?
• added relevant details to the changelog? (skip with label no-changelog)
• formatted title correctly? (take a look at the CONTRIBUTING and styleguide for details)

[codecov-commenter]

Codecov Report

Merging #1325 (fa31027) into main (1608edd) will decrease coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #1325      +/-   ##
==========================================
- Coverage   67.59%   67.59%   -0.01%     
==========================================
  Files         719      719              
  Lines       15879    15878       -1     
  Branches     1045     1045              
==========================================
- Hits        10734    10733       -1     
  Misses       4670     4670              
  Partials      475      475              

Impacted Files	Coverage Δ
.../contract/offer/ContractDefinitionServiceImpl.java	100.00% <100.00%> (ø)

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