CMake translations

[redtide]

• Added CMake for installation (will be used for AUR package) and Gettext translation builds
• desktop file built with CMake from a template
• EditorConfig file to respect indentation and other editing rules
• gitignore to avoid unneeded files mixed with others
• translation template file and Italian translation for testing

The translation seems not working yet, I need to get some practice with it, it's new to me using Gettext with Bash scripts, but AFAIU from documentation most of the work should be done already.

Note that the binary was renamed to .sh to ease the translation process, CMake will install it without the extension and with proper file permissions.

The desktop file was a bit modified, note the removal of the Encoding key, which seems to be a deprecated key

Feel free to edit the translation as needed. Qt Linguist can translate .po files but I suggest to install and use poedit, which can load .pot templates and create/update .po files from them. Hope to see this in Weblate :)

[stefonarch]

Translations and installation working fine, but "selected area" doesn't work anymore, either started from desktop file or cli. Selecting "window" under labwc opens the warning as it should and after selection is working.

[redtide]

Should be alright, including the combo to checkbox replacements.