CLI: Add checksum calculation to avoid unecessary processing when generating code

[jarlef]

Append checksum on the generated source code based on the input schema file + generator options (namespace + client name). This checksum is initial read on subsequent generation. If the input graphql schema and generator options hasn't changed, then the process can be aborted since the source code is up to date.

Purpose

I think the ZeroQL is a good framework to use as typed client for our backend tests. We output the schema file from our backend and then our xunit test project compiles the ZeroQL client as part of pre build step. Since ZeroQL.CLI tool is now baked into our build pipeline, we want optimise the performance. The best approach is to skip source generation when the generated code is up to date with the existing schema.

Benchmarks

Method	Mean	Error	StdDev
GenerateWithoutChecksumOptimization	7,640.75 us	151.703 us	141.903 us
GenerateWithChecksumOptimization	83.76 us	1.624 us	1.356 us

CLI

Added new option "Force" to skip checksum check and output generate source code (if this is somehow needed)

[byme8]

Can you add a test for this use case? A nice place would be the CLITests. It can check that if you execute commands twice, the second time should output The source code is up-to-date with graphql schema. Skipping code generation.

[byme8]

Overall nice addition! Thanks!

[jarlef]

I have updated the CLITests that checks both the outputted message but also checks that the write timestamp is also correct on the physical source code file. I also decided to add the ZeroQL.CLI version number into the checksum since a new version might produce different source code than earlier versions