frontend: Display toast when executing

[TheEvilSkeleton]

Description

This adds a toast whenever we want to run an executable from the list view:

Screencast.from.2023-02-23.17-13-28.webm

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update
• UI

How Has This Been Tested?

Please describe the tests that you ran to verify your changes.
Provide instructions so we can reproduce.

• Locally

[github-actions]

Pylint result on modfied files:

************* Module bottles.frontend.views.list
bottles/frontend/views/list.py:30:0: W1405: Quote delimiter ' is inconsistent with the rest of the file (inconsistent-quotes)
bottles/frontend/views/list.py:32:0: W1405: Quote delimiter ' is inconsistent with the rest of the file (inconsistent-quotes)
bottles/frontend/views/list.py:74:0: W1405: Quote delimiter ' is inconsistent with the rest of the file (inconsistent-quotes)
bottles/frontend/views/list.py:150:0: W1405: Quote delimiter ' is inconsistent with the rest of the file (inconsistent-quotes)
bottles/frontend/views/list.py:152:0: W1405: Quote delimiter ' is inconsistent with the rest of the file (inconsistent-quotes)
bottles/frontend/views/list.py:178:0: W1405: Quote delimiter ' is inconsistent with the rest of the file (inconsistent-quotes)
bottles/frontend/views/list.py:21:0: E0611: No name 'Adw' in module 'gi.repository' (no-name-in-module)
bottles/frontend/views/list.py:67:8: W0105: String statement has no effect (pointless-string-statement)
bottles/frontend/views/list.py:92:8: W0105: String statement has no effect (pointless-string-statement)
bottles/frontend/views/list.py:94:16: C0103: Variable name "w" doesn't conform to snake_case naming style (invalid-name)
bottles/frontend/views/list.py:74:8: W0612: Unused variable 'activate_handler' (unused-variable)
bottles/frontend/views/list.py:101:4: W0105: String statement has no effect (pointless-string-statement)
bottles/frontend/views/list.py:103:21: W0613: Unused argument 'widget' (unused-argument)
bottles/frontend/views/list.py:110:4: W0105: String statement has no effect (pointless-string-statement)
bottles/frontend/views/list.py:139:27: W0613: Unused argument 'widget' (unused-argument)
bottles/frontend/views/list.py:182:39: W0613: Unused argument 'event' (unused-argument)
bottles/frontend/views/list.py:182:51: W0613: Unused argument 'data' (unused-argument)
bottles/frontend/views/list.py:217:12: W0612: Unused variable 'name' (unused-variable)
bottles/frontend/views/list.py:18:0: W0611: Unused import logging (unused-import)
bottles/frontend/views/list.py:26:0: W0611: Unused Runner imported from bottles.backend.runner (unused-import)