Enable IL trimming and NativeAOT on AzureKeyVaultProvider

[edwardneal]

Description

We can safely enable IL trimming and NativeAOT support on the AzureKeyVaultProvider project for the .NET targets. This PR simply sets the IsTrimmable and IsAotCompatible properties.

This doesn't enable these features on SqlClient itself, and the addon isn't particularly useful on its own - but when the library itself is compatible, the addon isn't going to hold it back.

Issues

Relates to #1947.

Testing

The IL trimming and NativeAOT support is mostly flagged by compile-time warnings. A sample application which directly references the DLL runs successfully - I can successfully publish and run the code below.

const string AkvPath = "...";
var keyVaultProvider = new SqlColumnEncryptionAzureKeyVaultProvider(new DefaultAzureCredential(true));
var signedCMKM = keyVaultProvider.SignColumnMasterKeyMetadata(AkvPath, false);
var verifiedMetadata = keyVaultProvider.VerifyColumnMasterKeyMetadata(AkvPath, false, signedCMKM);

if (!verifiedMetadata)
    throw new Exception("Signed CMK metadata does not match.");

var cek = new byte[32];
var encryptedCek = keyVaultProvider.EncryptColumnEncryptionKey(AkvPath, "RSA-OAEP", cek);
var decryptedCek = keyVaultProvider.DecryptColumnEncryptionKey(AkvPath, "RSA-OAEP", encryptedCek);

if (!decryptedCek.SequenceEqual(cek))
    throw new Exception("Column encryption key does not roundtrip.");

I've not added a unit test - as per dotnet/runtime#97013 this isn't a good way to perform testing.

[paulmedynski]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 61.86%. Comparing base (55095ef) to head (7e3e3ad).
Report is 10 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3401      +/-   ##
==========================================
- Coverage   65.34%   61.86%   -3.49%     
==========================================
  Files         300      295       -5     
  Lines       65603    65321     -282     
==========================================
- Hits        42871    40412    -2459     
- Misses      22732    24909    +2177     

Flag	Coverage Δ
addons	?
netcore	66.91% <ø> (-1.63%)	⬇️
netfx	60.35% <ø> (-6.43%)	⬇️

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[benrr101]

I'd like to run this through our "official" AKV provider pipeline before accepting it - let me kick it off and see what we get. I'm guessing it'll be fine, but since I wrote the new AKV official pipeline, I just want to double check.

No changes required, just want to hold it until I can run the check.

[benrr101]

LGTM! (that stands for "Let's get this merged", right?)