Add search functionnality to IR Loader selector

Adding a new IR Loader from a directory search is possible , but it create a single mono IR Loader block.

Say, if you added a dual IR Loader block, and want to change one of the 2 IR you can either:

a) use the rotary knob (really convenient when then newly chosen IR is similary named, but not easy if the new IR has a really different name !)
b) tap the existing IR in order to choose another one , but then you only have a long list without any way to search …

Taping on one existing IR file in the IR Loader should bring the same search functionnality as in the main Directory browser.