Move drawable hit-object adjustment from skin/ ruleset configuration to stage and mod.

[andy840119]

Some of the skin components can be a part of the stage command.

Here's some example:

• Font/Font size
• Lyric Shader
• ...

The expectation for the skin module:

• Remove complex logic in the karaoke skin.
• Karaoke skin should be as simple as what other rulesets (especially the mania ruleset) did.

The expectation for the stage module:

• More commands for adjusting style-related properties (e.g. font, shader)
• Can override some behavior (e.g. change the font) by mod. mod should be able to read the ruleset config and remove/generate some necessary commands/elements for the stage.

[andy840119]

Here's the milestone:

M0 - Pre-process:

• Stage runner should possible to apply the change from mod. Use better way to provide stage command. #2309
• Define the interface for mod to modify the stage. e.g., stage info or stage command. Define the interface for mod to modify the stage. #2310
• Mod should be possible to decide can apply the change by stage info. Define the interface for mod to modify the stage. #2310
• Simply logic in the stage info. Simply logic in the stage info. #2312

M1 - Use the command pattern to apply the lyric style.

• Create a new place for the lyric style. Use command pattern to update the lyric style. #2314
• Remove the lyric style element. Use command pattern to update the lyric style. #2314

M2 - Use the command pattern to apply the lyric font.

• Create a new place for the lyric font.
• Remove the lyric font element.

M3 - Use the command pattern to apply the note font.

• Create a new place for the note style(or maybe just remove it).
• Remove the lyric style element.

M4 - Clean-up the skin

• Remove the layout definition element. Remove layout definition from skin. #2307
• Should be possible to remove the ElementType in the osu.Game.Rulesets.Karaoke.Skinning.Elements
• Should remove lots of binding and apply lyric style logic in the DrawableLyric.
• Should make sure that GetConfig cannot query by hit-object.

M5 - Refactor:

• ElementId and IHasPrimaryKey can be used in the stage element.
• In order to let customized property able to be transformer, should implement the IInterpolable for some classes. See the example of the MarginPadding.