dialects: (ematch) Add ematch dialect definitions

[jumerckx]

This can replace the existing eqsat_pdl_interp overrides. I'll also update the dialect name from tamatch to ematch in Tamagoyaki?

[codecov]

Codecov Report

❌ Patch coverage is 89.28571% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.16%. Comparing base (a4ee22a) to head (5c8fa3c).
⚠️ Report is 7 commits behind head on main.

Files with missing lines	Patch %	Lines
xdsl/dialects/ematch.py	88.67%	6 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5596      +/-   ##
==========================================
+ Coverage   86.15%   86.16%   +0.01%     
==========================================
  Files         392      394       +2     
  Lines       56271    56364      +93     
  Branches     6485     6492       +7     
==========================================
+ Hits        48478    48565      +87     
- Misses       6261     6267       +6     
  Partials     1532     1532              

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