bloop-maven: support per-execution configuration

[nigredo-tori]

Here we take scalac options etc. from the //plugin/configuration element in pom.xml. However, Maven has an option to override that configuration on a per-execution basis. This can be used, for example, to set different scalac options for compile and testCompile goals.

[tgodzik]

Thanks for reporting! Do you have an example of such a project? I would greatly help out figuring out the issue. We can use it for the tests to quickly check if everything is working properly.

[nigredo-tori]

I don't have an example project right now. I'll try and whip something up, but it'll probably be a couple of days.

[tgodzik]

Thanks!

[nigredo-tori]

Here's a tiny example. It has kind-projector plugin enabled using per-execution configuration, which Bloop import ignores. As a result, Maven can compile the project just fine, while Bloop fails, and Metals shows a compilation error.