Make Empty area in path bar open location entry (Ctrl+L)

I modified the pathbar so if you click the empty space to the right of it, it will open the "raw" location entry widget.

This is familiar to Windows users, and useful to those who don't know the Ctrl+L shortcut.

Demo video

https://streamable.com/7szmqt

Meta Notes

This project is very hard to contribute to casually, I spent 3+ hours setting up a runtime environment (and I already had flatpak and Builder installed!), trying to make GtkInspector work (I couldn't do it, I inspected my live version of Nautilus and compared).

I couldn't find a way to run the project without using Gnome Builder (I prefer other editors / CLI), as meson build complained about dependencies I couldn't obtain in my distribution (Ubuntu), and flatpak-builder seemed to pull all code from git (ignoring my modifications).

Also, modifying a single line and running the project in Builder takes 10+ seconds on my rather beefy machine, most of it spent in /usr/bin/meson --internal gettext install --subdir=po --localedir=share/locale --pkgname=nautilus.

Working on this topic might bring a lot of manpower (talented people might not have the time or temper to deal with this). At least a section in this document on how to hack using the terminal.