Rewrite and migrate V menu to ImGui

[mqrause]

Summary

Infrastructure "Rewrite and migrate V menu to ImGui"

Purpose of change

Migrate to ImGui and increase maintainability and expandability.

Describe the solution

Completely remake everything using ImGui.
Structurally this is heavily reliant on code I wrote when I started this before ImGui two years ago. It might be a good idea to refactor some of that, but for now I mostly want to get it functional.

Describe alternatives you've considered

There is no alternative (except for implementation details).

Testing

Press V and play around with it.

Additional context

Currently wip. Some basic functionality is implemented, so interested people can check it out and give feedback. The terrain/furniture tab won't be a part of the final version of this PR but is going to be added in another one.

[lgtm-com]

This pull request introduces 3 alerts when merging 0bf3591 into f889ed9 - view on LGTM.com

new alerts:

• 3 for Empty branch of conditional

[lgtm-com]

This pull request introduces 3 alerts when merging cb976c3 into d055515 - view on LGTM.com

new alerts:

• 2 for Constant return type on member
• 1 for Empty branch of conditional

[lgtm-com]

This pull request introduces 1 alert when merging 8c02583 into 158205f - view on LGTM.com

new alerts:

• 1 for Empty branch of conditional

[Zireael07]

Do we have a 'salvageable' label for PRs?

[mqrause]

I think I just need to ask a maintainer to reopen it when I continue working on it.

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions. Please do not bump or comment on this issue unless you are actively working on it. Stale issues, and stale issues that are closed are still considered.

[db48x]

I‌ know that you’re not finished yet, but I like what you’re doing and want to help you get it right. Here are a few comments about things that I‌ noticed as I‌ read the code.

[db48x]

When possible, prefer to just call ImGui::TextColored instead, as it does less work than cataimuig::draw_colored_text.

[db48x]

Better to just call ImGui::TextUnformatted in a loop than to repeatedly append to a string.

[db48x]

This and every other method here seem very verbose and duplicative. Perhaps something like this would be better:

   tab_data list;
   switch( selected_tab ) {
        case surroundings_menu_tab_enum::items:
            list = item_data;
            break;
        case surroundings_menu_tab_enum::monsters:
            list = monster_data;
            break;
        case surroundings_menu_tab_enum::terfurn:
            list = terfurn_data;
            break;
        default:
            debugmsg( "invalid tab selected" );
    }
    list.selected_entry->select_next();

They could be shortened further by putting the switch into a common method, perhaps called get_currently_selected_list. Then it would just be:

   get_currently_selected_list().selected_entry->select_next();

[mqrause]

Some of that can be simplified, yes. I did so with the filtering for example. But for some others it isn't that easy, because the tabs have different underlying data types (item, Creature, mapdata_common_t).

[mqrause]

Yeah, it's still very WIP, but that's good feedback!