Add tableau embedded-pair consistency test for adaptive SDIRK/ESDIRK

[singhharsh1708]

Summary

• Adds tableau_consistency_tests.jl: asserts sum(bi) ≈ 1 and sum(btilde) ≈ 0 for every adaptive SDIRK/ESDIRK method (the embedded-pair invariant sum(b) = sum(b̂) = 1).
• Catches the class of transcription error that silently breaks adaptive step-size control.
• ESDIRK659L2SA is @test_broken pending the coefficient fix tracked in ESDIRK659L2SA: invalid embedded error coefficients (sum(btilde)≠0) cause MaxIters on all adaptive solves #3659.

Checklist

• Appropriate tests were added
• Any code changes were done in a way that does not break public API
• All documentation related to code changes were updated
• The new code follows the
  contributor guidelines, in particular the SciML Style Guide and
  COLPRAC.
• Any new documentation only uses public API

Additional context

Add any other context about the problem here.