[Blame] Use GlAvatar for commit author

Problem to solve

This issue represents a finding from our work to audit features belonging to groupsource code. See the analysis in Figma for more information. See the overview video for guidance on how to review this analysis.

Screenshots

Proposal

• Address the following finding on the Blame page:
  • Use GlAvatar for commit author
  • There is an existing Pajamas solution to address this