Check whether new filter name exists in the database to avoid accidental overwrite

[minshao]

Resolves #125

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 66.66667% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 50.75%. Comparing base (cd759e1) to head (e851430).

Files	Patch %	Lines
src/graphql/filter.rs	66.66%	1 Missing ⚠️

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Additional details and impacted files

@@            Coverage Diff             @@
##             main     #126      +/-   ##
==========================================
- Coverage   50.75%   50.75%   -0.01%     
==========================================
  Files          65       65              
  Lines       10926    10928       +2     
==========================================
+ Hits         5546     5547       +1     
- Misses       5380     5381       +1     

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[msk]

• This PR needs to be rebased after Remove unused arguments #130 is resolved.

[sehkone]

@minshao , could you resolve the conflicts?

[msk]

could you resolve the conflicts?

Resolved the conflict. Please use "Squash and merge" to maintain linear history in main.