Change semi-sync information to use the parameter passed and deprecate enable_semi_sync

[GuptaManan100]

Description

This PR deprecates enable_semi_sync flag and changes the implementation for fixSemiSync to use the flag passed down from the RPC. Backup and RestoreFromBackup RPC's are also fixed to call SetReplicationSource when they finish. This is needed since the primary could have changed during the backup or restore process and the semi-sync settings need to be updated.

Related Issue(s)

#8975

Checklist

• Should this PR be backported? Some Part -> The change to the RPCs needs to be backported to maintain backward compatibility during upgrade downgrade process. Essentially we need vtctl on version 13 to work with vttablets from version 14. Backport: fix semi-sync for Backup and RestoreFromBackup commands by calling SetReplicationSource RPC #9730
• Tests were added or are not required
• Documentation was added or is not required

Deployment Notes

enable_semi_sync is deprecated and the user should be setting the correct durability_policy instead.

[deepthi]

Mostly LGTM. I had only one question.
Nice work!

[deepthi]

Is the relay log error from START or STOP?

[GuptaManan100]

We get it from StartReplicaton command to mysql. In our test environment we are using the FakeMySQLDaemon

// StartReplication is part of the MysqlDaemon interface.
func (fmd *FakeMysqlDaemon) StartReplication(hookExtraEnv map[string]string) error {
	if fmd.StartReplicationError != nil {
		return fmd.StartReplicationError
	}
	return fmd.ExecuteSuperQueryList(context.Background(), []string{
		"START SLAVE",
	})
}

and we set the StartReplicationError as -

goodReplica1.FakeMysqlDaemon.StartReplicationError = errors.New("Slave failed to initialize relay log info structure from the repository")

So we get the error in StartReplication, but it isn't seen in the Execute Super Query List