style: disallow space after object keys, other rules

add `disallowSpaceAfterObjectKeys` and associated changes.

add `disallowMixedSpacesAndTabs` (no files changed)
add `disallowMultipleLineStrings` (no files changed)
add `disallowNewlineBeforeBlockStatements` (no files changed)

Feel free to remove the other rules if not needed.

cc: @caitp