Backup & Restore README updates

[sagar-jadhav]

• Added jq as prerequisite in Backup README
• Removed http:// from the cluster image policy from troubleshooting section in Backup README
• Fixed counter++: not found & [[: not found issue install-velero.sh
• Incremented timeout in install-velero.sh
• Added echo statement in install-velero.sh to let user know that Velero installation is completed.
• Restructured and modified steps for IBM Common Services MongoDB restore
• Added restore doc for individual component restore
• Modified the complete CP4MCM restore doc
• Increased the wait time for checkPodReadyness
• Removed the icp-mongodb replicaset configure statements
• Modified the icp-mongodb restore job