Updated method reportTCresult with platformid

Hi Anton, 

we're running a Testlink 1.9.3 and I discovered that there were some changes in the testlink API in between 1.8 and 1.9 (can't pinpoint exactly which release).
The issue I ran into was that reportTCresult now requires platformid as well.
So I updated that and I think by looking at the branch graphics that your repo is the latest "master/main".
We might need to handle backwards compatibility, but I'm a bit unsure if there is a "officially supported" version of the Testlink API that this project supports, so I'm looking forward to any comments you might have.

Nice to meet you btw :-)