Add Path-Like Arguments for Querying Files

[ric-evans]

Introduces support for shortcut/base request arguments:

• "directory" and/or "filename"
  • query by directory path and/or the filename
  • Ex: {"directory": "/foo/bar"} -> ["/foo/bar/ham.i3", "/foo/bar/green.i3", "/foo/bar/eggs/ham.i3"]
  • Ex: {"directory": "/foo/bar", "filename": "ham.i3"} -> ["/foo/bar/ham.i3", "/foo/bar/eggs/ham.i3"]
  • Ex: {"filename": "ham.i3"} -> ["/foo/bar/ham.i3", "/foo/bar/eggs/ham.i3", "/beef/pork/ham.i3"]
• "path"
  • query by filepath (currently just a pseudonym for "logical_name")
• "path-regex"
  • query by regex

NOTE: With the exception of "directory" & "filename", these arguments are mutually exclusive

Order of precedence (decreasing):

1. "directory" & "filename"
2. "logical_name"
3. "path"
4. "path-regex"
5. "logical_name" sub-field within the "query" dict

closes https://github.com/WIPACrepo/file_catalog/issues/77

[ric-evans]

~Tests TBD~

Update: Now tested