Fix multiple issues in current PR by crating V2 APIs

[danmamsft]

The current APIs have two major issues:

1. the string returned back to caller doesn't include a length, so the caller cannot use memory safe str functions which requires length. This is caught by OneFuzz: https://dev.azure.com/microsoft/OS/_workitems/edit/53371227. The fix in V2 API is to return length as well
2. the C string returned to caller (both data blob and error string) is not freed, causing memory leak. The fix is to let caller allocates the memory and pass in allocated buffer. If the buffer is not pre-allocated or is too small, the V2 API will return buffer too small with the expected size for caller to reallocate the proper size.

one improvement made to encrypt and decrypt API is made the algorithm as a parameter

Test:
I have modifies testMoc.exe in IgvmAgent (please see my draft code in branch user/dama/testwrapperfix in Igvmagent repo for reference).
Here are the test I have done:
SecurityLoginV2: tested happy path; wrong/empty login file path; invalid/empty group name
CrateKeyV2: tested happy path to create both AES and RSA key; invalid/empty group name
KeyvaultKeyDecryptDataV2: tested happy path; buffer too small case (caller call API twice to get decrypt working); invalid algorithm; invalid groupName/keyvaultName; empty input data
KeyvaultKeyEncryptDataV2: same test coverage as decrypt.Also tested Encrypt and decrypt together and made sure decrypted data matches original plaintext
KeyvaultKeyCreateOrUpdateV2: tested happy path to create AES key and RSA key; tested invalid algorithm;invalid/empty groupName/keyvaultName
KeyvaultGetPublicKeyV2: tested happy path; tested return key empty; invalid/empty groupName/keyvaultName/keyName

Tested the onefuzz repro, with the fix, original error went away.

Tested with replacing igvmagent in a haas cluster. TVM is stopping and starting with no issue.

[SethBe]

[raghavendra-nataraj]

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[raghavendra-nataraj]

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[SethBe]

[SethBe]

[raghavendra-nataraj]

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