Enabled some optimizations

Previously to execute a homomorphic operation, BigInteger ciphertext was converted into a byte array and then back into a BigInteger. This release adds methods that can work directly with BigIntegers.

Big changes to public API + support for Spans

0.12.0

Added support for spans instead of array copying, added more tests, m…

Naming: PaillierExt -> Paillier

0.11.0

update secret tokens in gh actions and add RepositoryUrl to .csproj

Release NuGet Packages

0.10.2

Release nuget packages as artifact