Show lock icon in blob viewer

Problem to solve

When a file is locked, a lock 🔒 glyph is shown in the tree view, but not in the blob view. This means the visual designation is inconsistent.

Further details about current conditions

Tree	Blob

Proposal

Show the same locked glyph in both the blob and tree view for consistency.

On hover, should display tooltip saying "Locked directory" or "Locked file" for directory and blob respectively.

Directory	Blob