(UX Feature Request) Make the dropdown menu searchable for menus with many options

[NiC0x36]

Description

It's a bit hard to search for the desired language and currency under General Settings as the lists of the dropdown menus are very long.

Motivation

Better user experience, easier & faster to find the desired language and currency, less frustration. Smart feature that the user will appreciate.

Requirements

Write a list of what you want this feature to do.

1. Implement a searchfield in the dropdown menu similar to this:
   
   

Are you planning to do it yourself in a pull request?

No.

[cvarley100]

@digital-zen thoughts?