Bug 883278 - [contacts] importing from .vcf file (sd card) puts providedfirstname and lastname in firstname field if both contain only ascii characters, causes sort by lastname to fail [r=arcturus]

This commit does two main things:
  - Solves lack of Quoted Encoding recognition for the `fn` (First Name) field in VCF
  - Excludes `\r` as a meaningful character when parsing tuples.

It also includes some small style changes and unit tests for the fixed issues.