mTLS enablement in prometheus exporter

[MechMaster95]

Is your feature request related to a problem? Please describe.
we need mTLS enabled for encryption between harvest and prometheus instances for FIPS compliance.

Describe the solution you'd like
Enable mTLS options in the prometheus exporter block

Describe alternatives you've considered
Additional client Authentication along with the existing TLS is the only work around. this could be cumbersome.

Additional context
(#4078)

[Rakshitg600]

@cgrinds @MechMaster95
Is this issue still a priority ? I would like to work on it

[rahulguptajss]

@Rakshitg600 Yes, you can look into this. Thanks.