UX improvements

[Jeidnx]

Hey there,
Thanks for developing this script. No major hiccups for me thus far, though i would like to see a better user experience.
Two major things that i have noticed:

• There is no proper handling in case pass fails
• There is no feedback to the user to indicate if the password was successfully copied to clipboard

I forked the project and started work on implementing error and success handling trough notify-send, although i had some difficulties implementing this due to the many different pass calls and me not fully understanding the script. I will push my commits to jeidnx/wofi-pass and would really appreciate some advice / help there.