Settings for forcing/prefering single/double quotes for strings

Just a setting so quoting style can be unified across a codebase.

e.g.

for the three strings `abc`, `a'c`, `a"c`

`prefer_single_quotes` -> `'abc'`, `"a'c"`, `'a"c'`
`prefer_double_quotes` -> `"abc"`, `"a'c"`, `'a"c'`

`force_single_quotes` -> `'abc'`, `'a\'c'`, `'a"c'`
`force_double_quotes` -> `"abc"`, `"a'c"`, `"a\"c"`