fix adm control

[tpoignonec]

• add singularity detection
• revert to normal inverses (as opposed to choleski decomposition-based ones)
• various fixes

[github-actions[bot]]

Test Results

562 tests  ±0   359 :white_check_mark:  - 8   1s :stopwatch: ±0s  37 suites ±0   167 :zzz: ±0   35 files   ±0    36 :x: +8 

For more details on these failures, see this check.

Results for commit 13b975a6. ± Comparison against base commit 8175fc14.

:recycle: This comment has been updated with latest results.