add SIGNATURE_ALGORITHM as argument to CryptoRSA signature-methods

[steadyjaw]

Is your feature request related to a problem? Please describe.

I was trying to use this plugin to sign HTTP request with the REST plugin.
The API we're trying to talk to from the orchstrator needs an HTTP header signature signed with SHA256withRSA

unfortunately the CryptoRSAService only uses a SIGNATURE_ALGORITHM of NONEwithRSA and is not able to create signatures with another algorithm
https://github.com/vmware/o11n-plugin-crypto/blob/ca366a464f09ba855daef4cc3af22a98452841f6/o11nplugin-crypto-core/src/main/java/com/vmware/o11n/plugin/crypto/service/CryptoRSAService.java#L36

According to the Java documentation at least the following algorithms are standard:

• SHA1withDSA
• SHA256withDSA
• SHA1withRSA
• SHA256withRSA

It'd help me a lot, if the algorithms could be choosen as an argument on mehtods createSignature and verifySignature

Describe the solution you'd like

add argument String algorithm to methods:

• CryptoRSA.createSignature
• CryptoRSA.verfiySignature

• use provided algorithm in sign and verifySignatrure functions
• fall back to attribute SIGNATURE_ALGORITHM if no algorithm was provided
• at least the follwing algorithms are valid (according to java documentation)
  -- SHA1withDSA
  -- SHA256withDSA
  -- SHA1withRSA
  -- SHA256withRSA

Describe alternatives you've considered

No response

Additional context

No response