PascalCase naming inconsistencies with C#

[aaronfranke]

Godot version: 3.1.1 and master

Issue description: There are a lot of cases in the Mono module where the generated C# methods and properties are not using PascalCase properly. This is understandably due to this information not being present when these names are written out in snake_case. See also: #32734

In some cases, this also effects the editor, as the displayed name could be improved:

Here's my attempt to document what could be fixed:

Node:

• Callv -> CallV
• Editor__displayFolded -> Don't expose this?
• Rpc etc -> RPC etc
• Rset etc -> RSet etc?

Node2D:

• GetWorld2d -> GetWorld2D

Label:

• Valign -> VAlign
• Autowrap -> AutoWrap

Particles and Particles2D:

• FixedFps -> FixedFPS

PathFollow:

• RotationModeEnum Xy -> XY and Xyz -> XYZ

PathFollow2D:

• Lookahead -> LookAhead

Polygon2D:

• Antialiased -> AntiAliased
• Uv -> UV

RichTextLabel:

• Bbcode etc -> BBCode etc

Sprite:

• Hframes -> HFrames and get/set
• Vframes -> VFrames and get/set

TextEdit:

• Readonly -> ReadOnly

TileMap:

• CellClipUv -> CellClipUV
• GetCellv etc -> GetCellV or just GetCell (overloaded method)

TouchScreenButton:

• Bitmask -> BitMask
• TouchscreenOnly -> TouchScreenOnly

Tree:

• AllowRmbSelect -> AllowRMBSelect

Various players:

• Autoplay -> AutoPlay

VideoPlayer:

• BufferingMsec -> BufferingMSec

VisibilityNotifier:

• Aabb -> AABB

Misc:

• Aot -> AOT
• Rid -> RID in many places.

[aaronfranke]

Probably not going to be done for 3.2, and it would break C# compatibility, I suggest bumping to 4.0.

[neikeq]

Guess we can add a list of custom casing for words like these.

[neikeq]

I'm not keen of going all upper case for acronyms and some other words, like the following: AABB, AOT, RID, XYZ, RPC, HTML, HTTP, etc.

It can result in hard to read names:

• IsValidHTMLColor vs IsValidHtmlColor
• RPCCallMode vs RpcCallMode

I tend to agree with what is said here: https://www.approxion.com/capital-offenses-how-to-handle-abbreviations-in-camelcase/

The convention in .NET seems to be capitalizing only the first letter (e.g.: HttpClient), except for two-letter acronyms (e.g.: IO and 2D) where all letters are capitalized: https://docs.microsoft.com/en-us/dotnet/standard/design-guidelines/capitalization-conventions

Personally, I'd prefer it without the two-letter exception (I don't have a problem with Io and 2d). However, in this case, it's better to follow the convention. Specially now that so many node classes have 2D and 3D suffixes, which would make the difference with 2d and 3d in members too visible.

The only downside of following this convention is that currently we keep the original casing of Godot class names (e.g.: HTTPRequest). But for me that little inconsistency is ok, and I'd prefer not to keep that casing.

[marcinWlodarski]

100% agree with @neikeq - also bear in mind that https://en.wikipedia.org/wiki/Filename is a real word, having "file name" (and file_name, FileName, fileName etc.) was always a bit strange for me, since we have a single common word describing exactly what we have, and not some abstract "name" of a file.