add "Clear Log" button

[keturn]

Currently the Logging window shows logs from both the launcher and those it gets from the game.

After a few games, it's hard to navigate to the start of the current game. It'd be nice to have some kind of shortcut to different sections of the log, or more simply a "clear" button on the log view to remove the old content from the window.

[sankalpawadhiya]

I want to work on this project.

[skaldarnar]

@sankalpawadhiya you're welcome to do that!

Feel free to make open a PR early (in draft state) to receive feedback early on. You can also hop onto our Discord (https://discord.gg/terasology) for a direct chat, we've got a launcher channel there as well.