Since the first action of the list can be run directly with Enter while
the entry is focused, hitting "Down" means one wants to select the next
item of the list. So let's jump directly to the second item on the first
"Down" key pressed.
I now normalize with g_str_tokenize_and_fold() which uses standard
Unicode normalization.
I don't use g_str_match_string() directly though, because I want to
run additional checks to order the results by relevance. For instance
I still want actions whose labels starts with the search string to be
at the top, and results with same order as search token before those
with a different order. Then results with match in the tooltip. Finally
I also returns results with partial match in the label, and the rest in
the tooltip, though at the bottom of the list.
Other than that, this returns the same results as g_str_match_string()
with a similar algorithm. In particular now we only match the start of
tokens (a substring in the middle of a token won't match anymore).
I kept the small 2-character trick matching the first letters of the
first 2 words of the label, but I got rid of the fuzzy search (that none
really found ever relevant anyway).
This is useful for debugging though current consensus is that the finale
user should not care about the technical name of an action.
I did also some minor code cleanup when setting up the model columns.
Fix various bugs, improve code design and efficiency, change feature
name, update the feature up to our standards (now uses GIMP preferences,
session management, less overwhelming settings...).
Also now action history is tightly tied to GimpAction and logs all
action activation (however it activates, and the show_unavailable
parameter also applies to history).
Search algorithm greatly improved with basic tokenization, better
ordering, filtering, etc.
