R1:4a0d3ba3e14b

Locate File: allow to search './path/to/something.txt'

Summary:
Before this change, if you search a file using Locate File,
this was the only accepted syntax for a full-path:

path/to/something.txt

After this change, some relative/absolute Unix-like variants
are also accepted:

./path/to/something.txt
/path/to/something.txt

Similar prefixes can be frequent when you quickly copy-paste things
from shell commands like 'grep' or 'find' etc.

Ref T15508

Test Plan:
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