fix: poseidon2 templates

[yelhousni]

Description

This PR:

• corrects matMulExternalInPlace for width%4=0,
• removes matMulM4InPlace in curves templates as only width=2,3 are supported,
• adds diagonal of internal matrix for goldilocks when width=12 (sponge),
• adds regression test for goldilocks when width=12.

Type of change

• Bug fix (non-breaking change which fixes an issue)

How has this been tested?

TODO:

• implement cross tests with other libraries who share the same parameters.

How has this been benchmarked?

N/A

Checklist:

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I did not modify files generated from templates
• golangci-lint does not output errors locally
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules