WorldTool is a powerful and feature-rich world-editing Minecraft data pack.
Here, you can download non-full releases (experimental versions) to try out.

To make some neat features possible, such as undoing, WorldTool uses PlayerDB.

Type /function worldtool:give to give yourself all tools.

More info in the full documentation (not up-to-date with experimental versions):
https://ellivers.github.io/worldtool-docs

If you want to help translating WorldTool to other languages, you can do so here:
https://crowdin.com/project/worldtool

If you have any questions, feel free to ask in the Discord server:
https://discord.gg/jn8d4zb