feat[close #24] Add --dry-run option

[mirkobrombin]

close #24

I am unable to test due a problem with ABRoot which afflict my installation since weeks:

  ERROR   building at STEP "LABEL maintainer 'Generated by ABRoot'": error decoding response from copier subprocess: invalid character '(' looking for beginning of value
Error: building at STEP "LABEL maintainer 'Generated by ABRoot'": error decoding response from copier subprocess: invalid character '(' looking for beginning of value

[kbdharun]

The locale changes LGTM, will lock the component on Weblate to prevent merge conficts after this PRs merge.

[matbme]

Needs some extra checks to avoid doing destructive operations:

• This section deletes the current image, which should not happen in a dry-run
• This entire section makes changes to the future partition
• This part writes to the init partition
• This part does more changes to the future partition

I think a dry-run should enter these functions and skip the write operation. If we modify part-future, the future partition may become unusable and it's not a dry-run anymore

[mirkobrombin]

Needs some extra checks to avoid doing destructive operations:

• This section deletes the current image, which should not happen in a dry-run
• This entire section makes changes to the future partition
• This part writes to the init partition
• This part does more changes to the future partition

I think a dry-run should enter these functions and skip the write operation. If we modify part-future, the future partition may become unusable and it's not a dry-run anymore

Following our discussion on Discord, I moved the image removal after the dry run and made the dry run exit earlier, skipping the init partition. For the other sections, ABRoot is writing inside .system.new, not the actual .system folder, so it is fine.