Application: Fix crash; Remove unnecessary command_line override

[ryonakano]

Fixes #11

Changes Summary

• fix: Prevent crash on startup
• refactor: Remove unnecessary command_line override in favor of arg_data field in OptionEntry

[teamcons]

Do not worry about the Linter - We still have to clean up the old code

I will check when i have time for this
Much thanks for your efforts :)

[teamcons]

Cannot test for ARM, but works as usual here so LGTM

[teamcons]

thank you!

[teamcons]

I somehow didnt catch that (i thought it was libportal quirk), but this implementation works only when the app was previously closed.
If i call it when a window is already there, it stays in the remote instance, and the primary Cherrypick instance ignores it.

Ive spent a lot of time trying to make something like this work without a command_line override in another app, but to properly handle desktop actions, it seems necessary.
Except for Switchboard which handles it as an open(), all other eOS apps with Desktop Action act the same: if the app is already open, the desktop action does nothing, because it isnt picked by the primary instance

https://valadoc.org/gio-2.0/GLib.ApplicationCommandLine.html