Add the ability to refresh the package list with a button

[stevenbenner]

Discussed in #6

^{Originally posted by majestic53 March 3, 2022}
I noticed that if I removed a package while pacfinder is open, the package will continue to be listed in the app. Would it be possible to add a refresh button and/or allow refresh through CTRL+R?

[stevenbenner]

Added in commits:

• 1ec172c
• bddbb57
• 1172d03
• 0e8c540

This will be included in the next release (version 1.2).