Migrate ECF to GitHub

We want to move ECF to GitHub.

This is the general plan:

• SL -> Scott Lewis (PL) to ratify the move and my involvement
• WM -> Create eclipse/ecf on github
• WM -> Give rights to @wimjongman to fool around with actions, milestones, discussions,etc..
• Us -> Push to github
• Us -> Fix the foundation build to build on master pushes
• Us -> Create github actions for pull request validation
• WM -> Close bugzilla
• Us -> Open github issues
• Us -> Make a "We have moved" topic in the ECF forum
• WM -> Make the topic ^^ sticky
• WM -> Close the forum
• WM -> Open github discussion
• Us -> Fix the project page
• Us -> Fix links on websites and wiki