Improve cold fragment name matching

Summary:
Fix cold fragment name matching regex by replacing existing
regexes `.*\.cold\..*` and  `.*\.cold`
and combining them into `.*\.cold(\.\d)?`,
applied to restored name (with BOLT-added suffixes stripped)

This allows matching names like "execute_stack_op.cold/1", which
previously weren't recognized.

(cherry picked from FBD24804880)