EdkRepo Sync Flow Change: When a manifest update is required abort the sync operations unless -o or -u is specified

[ashedesimone]

Currently if the sync command detects that a manifest update is detected it will alert the user and proceed with the sync operations. This results in the user needing to immediately re-run the sync command with the -u flag and conduct an additional sync.

The sync command should be updated such that if a manifest change is detected the command will abort unless the -u or -o flags are used. When the command is aborted the user should be notified that a manifest update is available and that they can complete the sync and update their manifest by using the -u flag or they can bypass the update and complete the sync by passing the -o flag.