Simplify Build Script

[nikeee]

This is filled by a script that runs in the CI build:

// 1.0.0-beta.2+deadbeef
// These info is filled by build script
public const string VersionFormal = "%VERSION%"; // 1.0.0
private const string ReleaseSuffix = "%RELEASE-SUFFIX%"; // -beta
public const string CommitsSinceTag = "%COMMITS-SINCE-TAG%"; // .2
public const string CommitId = "%COMMIT-ID%"; // +deadbeef

Maybe we can use ThisAssembly.Git for that.

[nikeee]

Depends on #176