feat: Add deactivate only mode

[mzaniolo]

Closes #38

[github-actions]

LCOV of commit 5acdabc during Rust workflow #294

Summary coverage rate:
  lines......: 81.2% (462 of 569 lines)
  functions..: 32.1% (123 of 383 functions)
  branches...: no data found

Files changed coverage rate:
                |Lines       |Functions  |Branches    
  Filename      |Rate     Num|Rate    Num|Rate     Num
  ====================================================
  src/config.rs |95.6%    136|34.7%   219|    -      0
  src/lib.rs    |96.6%     59|30.8%    26|    -      0
  src/zitadel.rs|77.4%    239|27.5%   102|    -      0

[emgrav]

I have one question about the functionality and a tiny nit about a comment, but looks quite good otherwise.

[emgrav]

LGTM

[sirewix]

Can you add some lines to the readme and/or config sample on how cache behaves when this mode is enabled. From what I see the cache is written as if all changes were processed, so it wouldn't be possible to run with disable_only and then without and get every change processed that wasn't processed during disable_only run.

[mzaniolo]

Can you add some lines to the readme and/or config sample on how cache behaves when this mode is enabled. From what I see the cache is written as if all changes were processed, so it wouldn't be possible to run with disable_only and then without and get every change processed that wasn't processed during disable_only run.

Well, I think we should first be ask how we want the cache to behave when deactivate only is set. The issue doesn't say anything about it. Does anyone know how to answer that? Maybe @nikzen ?