Add backslash path regex match as an exception to string regex

[chadcurtis]

Add backslash path regex match as an exception to string regex for paths with backslashes.

This change is an attempt to address the behavior reported in #5, in which a path with a backslash (\example\path\to\thing\) resulted in the query segment not being matched to any known type. The reason for the path's exclusion is due to the regex for STRING intentionally excluding anything that has \ present (potentially to avoid recognizing other escape/syntax a strings).

This change adds an extra matcher to the STRING regex that attempts to account for generic alphanumeric paths with/without spacing.