port #989 to new branch due to lack of perms to fix conflicts

[collerek]

Allow indexing on foreign keys

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (52d992d) to head (7338e49).

Additional details and impacted files

@@            Coverage Diff            @@
##            master     #1276   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          203       203           
  Lines        14791     14806   +15     
=========================================
+ Hits         14791     14806   +15     

Files	Coverage Δ
ormar/fields/foreign_key.py	100.00% <100.00%> (ø)
...sts/test_model_definition/test_model_definition.py	100.00% <100.00%> (ø)

[codspeed-hq]

CodSpeed Performance Report

Merging #1276 will degrade performances by 18.1%

_{Comparing allow-setting-index-on-fk (7338e49) with master (52d992d)}

Summary

⚡ 1 improvements
❌ 2 (👁 2) regressions
✅ 81 untouched benchmarks

Benchmarks breakdown

	Benchmark	master	allow-setting-index-on-fk	Change
⚡	test_avg[1000]	16.4 ms	14.2 ms	+15.01%
👁	test_max[1000]	13.3 ms	16.3 ms	-18.1%
👁	test_max[500]	10.3 ms	12.3 ms	-16.98%