fix(IsLoadableModule): return false for abstract classes

[OverwrittenCode]

Description

IsLoadableModule did not check the property TypeInfo.IsAbstract. Therefore, an unnecessary warning log stated that it could not be loaded.

Now, if a class is abstract, it will be ignored safely and all the inheritors will continue to load any commands.

Changes

• fix(IsLoadableModule): return false for abstract classes
• fix: handle other attributes
• refactor: simplify attribute logic
• fix: correct terminology in debug message

Related Issues

N/A

[OverwrittenCode]

@Cenngo your suggestion looks completely fine - I have:

• Accepted your suggestion and slightly modified it so the switch statement is no longer needed.
• Corrected the debug message

Do you think we can mark this PR as Ready for review?

Hold on, we might be missing some.

Screenshot of the src/Discord.Net.Interactions/Attributes/Commands folder for reference:

• AutocompleteCommandAttribute
• ComponentInteractionAttribute
• ContextCommandAttribute
• MessageCommandAttribute
• ModalInteractionAttribute
• SlashCommandAttribute
• UserCommandAttribute

Should I include MessageCommandAttribute and UserCommandAttribute before marking this PR ready for review?

Also, it may help to sort the is pattern matching alphabetically so it is easier to compare to the source folder.