Properly escape "%" when doing wildcard URL search

[ctengel]

Action:

• GET /file/?url=file://hostname/path/that%20includes/pct%20signs/*
• essentially, % is needed for URLs in some cases and may be in the URL itself

Expected response:

• just subdirectories of that directory

Current

• it may wildcard match other directories anyplace a % is in
• not tested

Fix:

• escape "like" string before adding the % on the end so any % goes into postgres as \% and is interpreted as a literal %