Update bin/secpick to allow wait after failed cherry-pick

What does this MR do and why?

Update bin/secpick to allow wait after failed cherry-pick

When running bin/secpick, often you'll find that the cherry-pick command fails and then you have to manually fix the issue and figure out which commands would have been run and run them yourself.

This change pauses if the cherry-pick failed and instructs the user to fix the conflicts then run git cherry-pick --continue and then continue the bin/secpick script.

NOTE: I don't have a branch I can actually test this with as this branch already exists but the git_push_commands are successfully triggered when pressing y so should be enough to confirm this works as intended.