Support optional-chaining

[Serabe]

Optional chaining is currently at stage 3 and already shipped with TypeScript 3.7. Currently, with the following input:

const obj = {};
obj?.prop?.subprop;

We get the following output:

const obj = {};
obj ? .prop ? .subprop;

Notice the extra spaces around ?. The expected output is the same as the input.

Configuration:

{
"indent_size": "4",
"indent_char": " ",
"max_preserve_newlines": "5",
"preserve_newlines": true,
"keep_array_indentation": false,
"break_chained_methods": false,
"indent_scripts": "normal",
"brace_style": "collapse",
"space_before_conditional": true,
"unescape_strings": false,
"jslint_happy": false,
"end_with_newline": false,
"wrap_line_length": "0",
"indent_inner_html": false,
"comma_first": false,
"e4x": false,
"indent_empty_lines": false
}

[Serabe]

Submitting a new issue as @bitwiseman said in #1530 that each item should get its own issue to be tracked.