Added support for typeLiteral.separatorKind.multiLine: newLine

[DoctorGester]

• I don't know if such a feature is even needed for general public
• I don't know if any of the code is good (first time editing Rust source)

This adds support for newLine separator specifically for multiline type literals. If not specified, it will fallback to whatever is specified in typeLiteral.separatorKind (implemented poorly).

[CLAassistant]

All committers have signed the CLA.

[dsherret]

Hey @DoctorGester, I'm sorry, but this was discussed and closed in #454

For example, this is already possible when not using semi-colons like so: https://dprint.dev/playground/#code/C4TwDgpgBAKhDOwoF4oG8CwAoKurAWAC4pEAnASwDsBzAbmzygHtgALCMkqgVwFsARpwZYAvkA/config/N4WAUABBBEA2CWA7ApgdXgEwC4AtoC4IAOABgBpwpokNlEt1s9CAmCyGAZ2QFt4BhAPaxBiTgRgBDTvGjgAvuCA/language/typescript

Are you wanting to use semi-colons, but here to not use semi-colons?

[DoctorGester]

Hi, @dsherret yep exactly, I wanted semicolons in the rest of the code, but not in types since types are less ambiguous in general
Feel free to close the PR if it's not needed!