Convert to west extension

[beriberikix]

https://docs.zephyrproject.org/latest/develop/west/extensions.html#adding-a-west-extension

This is a very convenient script, thank you for creating it! As I start to use it I felt like it would be easier for the user if it was a proper west extension. At the same time, west has most (all?) the context already of things like compiler path, source directory and build directory, so the extension should be able to automatically figure it out.

[smrtos]

Sorry for the late response. I was not an expert of west when I worked on this script.
And thank you for the interesting suggestion. I will give it a try.

[beriberikix]

Did you get a chance to try? Would love to test it!