[minicern] reduce code duplication to easen debugging

[ferdymercury]

Non-functional change, it just reduces duplicities and more than 2500 lines of code

[github-actions]

Test Results

    22 files      22 suites   3d 11h 0m 49s ⏱️
 3 849 tests  3 849 ✅ 0 💤 0 ❌
76 935 runs  76 935 ✅ 0 💤 0 ❌

Results for commit b3c9374.

[ferdymercury]

Suggested change

	C=== fcz.inc ===================================================
	C=== fzc.inc ===================================================

[dpiparo]

Thanks for this huge refactoring. I was wondering if the structure of the commits is to bekept or whether you imagined squashing (some of) them.

[ferdymercury]

Thanks! I think it's easier to review them one by one, but once it's approved you can squash them into a single one, or whatever N you consider useful, I don't mind :)