Safely decode commit blobs for "Show Commit"
Safely decode commit blobs for "Show Commit"

Ref #1371

"Show commit" (and the details panels from the "Repo History") are
read-only views.  Throwing is not an option here as seen in #1371.

Instead show a warning and the partially ("safe") decoded output.

divmain/GitSavvy,divmain/GitSavvy,divmain/GitSavvy