Add how-can-i-help page to Plinth

Created by: SunilMohanAdapa

We are currently showing list of Debian packages that need help when apt is run. This is only available people are using apt from command line which is rare for our case. Also we need to show ways to contribute to FreedomBox.

We need to create a page in the help section of the Plinth to show list ways people can help FreedomBox/Debian. This page should contain information about:

• Link to FreedomBox/Contribute page
• Link to translation using Weblate
• Show list of packages needing help using how-can-i-help package (perhaps in a separate tab so as not to make a web request everytime).

After this, remove how-i-can-help integration from apt:

• It causes very significant delays to the apt install process
• Makes a web request to show the information violating the privacy of the user. Consider completely removing the how-can-i-help package as it's function is very minimal and information can be fetched directly from https://udd.debian.org/how-can-i-help.json.gz.