Excise MatrixAlgebra module entirely to use MatrixAlgebraKit

[kshyatt]

Moved one! and safesign out, changed a few calls to leftorth!, and the tensors and diagonal tests passed locally for me. Hopefully this won't break anything downstream...

[codecov]

Codecov Report

❌ Patch coverage is 90.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 80.12%. Comparing base (8549b2a) to head (59bdfd8).
⚠️ Report is 5 commits behind head on matrixalgebra.

Files with missing lines	Patch %	Lines
src/tensors/factorizations/factorizations.jl	50.00%	1 Missing ⚠️

Additional details and impacted files

@@                Coverage Diff                @@
##           matrixalgebra     #272      +/-   ##
=================================================
+ Coverage          78.02%   80.12%   +2.10%     
=================================================
  Files                 49       49              
  Lines               5760     5570     -190     
=================================================
- Hits                4494     4463      -31     
+ Misses              1266     1107     -159     

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[lkdvos]

Left some small comments, happy to already merge this though if you prefer. I definitely like this, it's great that we no longer need this module!

[kshyatt]

OK, all comments resolved, should be good to go