[Feature]: Add possibility to specify annotations for the CronJob that is created by MongoDBBackupPlan

[vusalalishov]

Is your feature request related to a problem? Please describe.
We use linkerd as a service mesh solution, and its container is injected in the pods by default. Since linkerd container runs forever, we get a pod for a job that never terminates, since there is at least 1 container running.

Describe the solution you'd like
One of the possible solutions could be to provide a possibility to specify additional annotations for the CronJob and Job, using which we can add: linkerd.io/inject: false annotation, which will prevent linkerd injection.

Describe alternatives you've considered
There might a plenty of different approaches to solve this problem, for example: do not inject linkerd by default in all pods and control it manually.

Additional context
None