Implement Roslyn formatting options in the decompiler

[siegfriedpammer]

As we are now part of Roslyn, it would be nice to support all the formatting options that Roslyn exposes (plus new ones dotnet/roslyn#25303).

1. Copy Roslyn's CSharpFormattingOptions into ICSharpCode.Decompiler.CSharp.Output replacing all options with plain bool/enum properties, so we use the same names as Roslyn does for the options, but don't have a dependency on Roslyn.
2. Implement the options in CSharpOutputVisitor.
3. Extend the Roslyn integration to pass the current options to the decompiler.

[dgrunwald]

Alternative idea: translate from our syntax tree to the Roslyn SyntaxTree, and use the existing Roslyn formatters.
Or even: write a code generator that converts the immutable Roslyn SyntaxTree into a mutable SyntaxTree, and also auto-generates a conversion function from the mutable SyntaxTree to the original Roslyn SyntaxTree. Then port the decompiler to use that newly generated SyntaxTree.
However, I don't think the Roslyn syntax tree structure is quite suitable for ILSpy, e.g. we do some fancy tricks with DirectionExpression wrapping/unwrapping, so this approach might run into problems. But I do think the current syntax tree design from NRefactory is not all that great a match for ILSpy (the linked list structure is problematic, e.g. in #1202). Maybe just generate a new one using a specification in .tt file, the same way we generate the ILAst?
Lots of open questions here...

[siegfriedpammer]

See also #603 and #1079