Clean commits

[stappersg]

This issue is for having a place to elaborate upcoming merge requests for me.
Some of those _MR_s will have @marlonbaeten as author.

Goal of this issue is having clean commits. Assumed is that we know that the reason for clean commits is that it is a way to tell our future selfs and co-workers what did change and for which reason.

[stappersg]

There are now this merge requests

• Revert two commits #71 Revert two commits (GS)
• String change #74 String change (MB)
• Move sample messages to Rust test #77 Move sample messages to Rust test (MB)
• Implemented CID #78 Implemented CID (MB)
• Return que id #79 Return que (GS+MB)

It is #78 that shows how #62 was fixed, and #79 does that for #64

[stappersg]

The above references are the advised sequence to merge. Now in text:

• Revert two commits #71
• new file: backend/examples/crabfeeder.rs #82
• new file: samples/normal.eml #84
• Added CID email to samples #83
• Implemented CID #78
• String change #74
• Return que id #79

After that, we find out how much rebase work for #80 and #85 is needed.

[marlonbaeten]

Hi Geert, I really appreciate the effort you put in to this, with the goal to make Mailcrab even better.
Unfortunately I'm not convinced that reverting commits, and then re-applying them makes the history easier to understand. You are right that it might be better to split work into logical and small commits, I'll try my best next time.
Anyway we have this issue together with your PR's as a public record for the reasoning for all these changes.

I'll close the PR's for now - could you maybe base the version commit on main? I be glab to merge that.

[stappersg]

be better to split work into logical and small commits

Example given #91