* Focus into the LineEdit, then perform input to search the list of events by the events assigned.
* New specialised editor-only control for this: EventListenerLineEdit. Line edit is a good candidate for such a control because you can focus it, override it's input handling, and show the event all in one control.
Update InputEventConfigurationDialog to use event listener line edit rather than the separate tabs.
* Cleaner look - no need for tabs.
* Simpler code.
Adds a new, cleaned up, HashMap implementation.
* Uses Robin Hood Hashing (https://en.wikipedia.org/wiki/Hash_table#Robin_Hood_hashing).
* Keeps elements in a double linked list for simpler, ordered, iteration.
* Allows keeping iterators for later use in removal (Unlike Map<>, it does not do much
for performance vs keeping the key, but helps replace old code).
* Uses a more modern C++ iterator API, deprecates the old one.
* Supports custom allocator (in case there is a wish to use a paged one).
This class aims to unify all the associative template usage and replace it by this one:
* Map<> (whereas key order does not matter, which is 99% of cases)
* HashMap<>
* OrderedHashMap<>
* OAHashMap<>
