Some Issue Fixing, Add missing Stats values(additions, deletions, total) to CommitResponse, Add .net5 Support

[MypowerHD]

Hello i have some Changes for you,
I was missing the Stats Values in the Commit Response, so i add them.

There was several Naming Issues, theyr fixed now, an issue with an Try Catch where you not able to get the stacktrace when it would throw.

Do Not:

try
{
    // Do stuff that might throw an exception
}
catch (GitLabException e)
{
    if (e.HttpStatusCode == System.Net.HttpStatusCode.Forbidden) //Filter out Forbidden StatusCode
        return false;
    else
        throw e; // This destroys the strack trace information!
}

Do:

try
{
     // Do stuff that might throw an exception
}
catch (GitLabException e)
{
    if (e.HttpStatusCode == System.Net.HttpStatusCode.Forbidden) //Filter out Forbidden StatusCode
        return false;
    else
        throw; //This preserves the StackTrace
}

[jetersen]

Blocked by net5 release