DolphinWX: Allow short-hand searching in the code window

Lessens the restrictions on the searching in the code view.
Now typing out the full 8 digit hex number isn't needed. For example, you don't need to type 000000FF to go to FF, you just literally type FF.

Also makes JumpToAddress a boolean function to remain consistent with the DSP code view.

This will also change the address search box to have a red background if
either an invalid hex number is given, or if it's longer than 8 characters