Feature: Object class selection string filtering

[perezdidac]

Motivation / Problem

Players can use NewGRF in a new game, and some of them contain objects than can be placed on the map. To make it easier for players to browse throughout the list of object classes, this pull request adds a text edit box to the Object Selection window so object classes can be filtered by.

Description

Adding a filter for object classes in the Object Selection window.

Limitations

Note that object classes are filtered by objects themselves are not.

Highlights

• Selection gets preserved when filtering
• Always a class selected if filter removes all
• Re-opening the window selects the previous object class and object
• Starting a new game too, but only if the corresponding NewGRF is still available.

I plan to do the same for stations next probably. Or vehicles?

Checklist for review

N/A

[J0anJosep]

You have a warning that should be checked.

[J0anJosep]

You have a warning that should be checked.

Hi Joan Josep, I don't see the warning, where is it?

Check the CI results. Also, under "Files Changed" you have references to the warning.

[stormcone]

I found some code style and documentation issues.

[LordAro]

No real issues

[perezdidac]

No real issues

Thank you! Addressed your comments.

[TrueBrain]

@perezdidac : just for future learning, if you resolved an issue, you can just hit the "Resolve conversation" button without leaving a comment :) Saves you a lot of time, saves us from reading acknowledgements :D Cheers!