Building a snapcraft package with web-view as dependencies

[Full detail](https://forum.snapcraft.io/t/running-a-rust-app-with-libwebkit2gtk-dependency/6952/4)

TL;DR:

I had no problem and building and running the rust app in my workstation.
Publishing and installing the snap package and running it however, will have this error.
```
Gtk-Message: Failed to load module "canberra-gtk-module"
Gtk-Message: Failed to load module "canberra-gtk-module"

** (svgbob-desktop:20418): ERROR **: Unable to fork a new child process: Failed to execute child process "/usr/lib/x86_64-linux-gnu/webkit2gtk-4.0/WebKitWebProcess" (No such file or directory)
Trace/breakpoint trap
```
However, trying to launch the binary snap package created in the $SNAP directory
```sh
/snap/svgbob-editor2/current/bin/svgbob-desktop
```
would launch the app with no problem, since I have the webkit gtk installed in my workstation anyway.
It wouldn't be the same thing when other users want to use my snap package.

I think this has to do with how rust links the dependencies and is not the same way as snacraft expected it to be.