Check dependency versions at runtime

[amezin]

Most distros update all GNOME components together. However, for example, on source-based distros, it is possible to build a new GNOME Shell with old versions of GLib or GJS. Sometimes, Ubuntu or Fedora release with some outdated dependencies.

But supporting such configurations is almost completely pointless, and it will be hard to test.

Instead, ddterm should check versions of:

• GJS
• GLib
• Vte
• Gtk
• Handy/libAdwaita
• Anything else it'll depend on in future

And show a warning if unsupported versions are detected - both as a message box and as a log message.

[amezin]

Current requirements:

• GLib >= 2.79.0 (stable 2.80) app: expect GApplicationCommandLine.done() to be available #1618
• VTE >= 0.75.0 (stable 0.76) app/terminal: drop context menu implementation for Vte <0.76 #1599
• GJS >= 1.78.5 for WeakRef. .connect_object() will require 1.79.1 (stable 1.80)