feat: ACMG rating of sequence/small variants (#54)

[gromdimon]

Tasks:

• Implement
• Test

[codecov]

Codecov Report

Merging #60 (5923126) into main (cc378b8) will increase coverage by 9.60%.
The diff coverage is 90.90%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #60      +/-   ##
==========================================
+ Coverage   87.98%   97.59%   +9.60%     
==========================================
  Files          33        2      -31     
  Lines        1124       83    -1041     
  Branches      339        0     -339     
==========================================
- Hits          989       81     -908     
+ Misses        131        2     -129     
+ Partials        4        0       -4     

Files Changed	Coverage Δ
backend/app/main.py	97.56% <90.90%> (-2.44%)	⬇️

... and 31 files with indirect coverage changes