Update Nuget packages and implement new EdDsaSignatureProvider.Verify function

[NzKyle]

This is a new version of #9.

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This PR does a few things:

Updated all Nuget packages to their latest versions.

Implements a new Verify(byte[] input, int inputOffset, int inputLength, byte[] signature, int signatureOffset, int signatureLength) override in EdDsaSignatureProvider as well as a corresponding Verify function in EdDsa.

The new Verify function was added into Microsoft.IdentityModel.Tokens.SignatureProvider in the following PR - and was causing validation failures when validating signatures on tokens signed with EdDSA.

I also implemented some tests to confirm that new functionality is working as expected.

As a side note I noticed that 6 of the PasetoTestVectors.ValidateToken_ExpectCorrectResult tests are failing when I run them locally - these were failing before I upgraded any nuget packages - and continue to fail after the update - so I didn't make any changes to them.

[NzKyle]

@scottbrady91 - with regards to your question on #9 - the new method in Microsoft.IdentityModel was added in version 6.23.0.

The tests that were failing on the v2 branch are also failing on the master branch.

[dandry]

Hello, @NzKyle @scottbrady91 is there any way I could help pushing this further? Really looking forward to have this change merged :)

[scottbrady91]

Hi both, sorry for the delay. I'll merge this one in this weekend. Since this is a breaking change (it's not backward compatible with older versions of Microsoft.IdentityModel), I'll release a v3 of this library asap.