Add option/button to copy URLs without query parameters

[atc0005]

Currently these buttons are provided:

• Decode
• Copy to Clipboard
• Reset
• About
• Quit

Not sure if providing a checkbox to strip URLs of query parameters would be the way to go or if a separate button would be (plenty of room still on the bottom "bar").

Also not sure if all URLs should be copied without query parameters or just when the decoded output consists of a single URL. If a checkbox is provided to toggle the behavior, then presumably it would apply to all URLs.