Revise Git commit hash handling

[rubo]

Changes

• Removed dependency on Git executable in project files
• Added Microsoft.Build.Tasks.Git package to incorporate the commit hash into the version string
• Stopped copying the .git directory to Docker containers, which significantly increases local Docker image build times
• Revised ClientVersionV1 tests
• Removed the branch name check from the project file so as not to fail the build because of an undesired branch name. This logic is completely unrelated to the build process and must be handled at the GitHub level

Types of changes

What types of changes does your code introduce?

• Bugfix (a non-breaking change that fixes an issue)
• New feature (a non-breaking change that adds functionality)
• Breaking change (a change that causes existing functionality not to work as expected)
• Optimization
• Refactoring
• Documentation update
• Build-related changes
• Other: Description

Testing

Requires testing

• Yes
• No

If yes, did you write tests?

• Yes
• No

Documentation

Requires documentation update

• Yes
• No

[michaelsproul]

Was Nethermind returning a commit hash with length < 8 prior to this change? We are getting errors connecting LH to Nethermind v1.26:

Jun 06 03:04:48.001 WARN Execution engine call failed error: InvalidClientVersion("Input must be exactly 8 characters long (excluding any '0x' prefix)"), service: exec

[smartprogrammer93]

@michaelsproul it used to return longer than 8:
#7013