Restructure project to allow for splitting up Gradle plugin

[adam-enko]

• Convert buildSrc to build-logic, so utils/conventions can be re-used in other included builds.
• Introduce convention plugins for common config, and publishing (replacing kotlinx.team.infra, which is not compatible with modern Gradle approaches)
• Workaround Gradle issue with running tasks in included builds Support invoking task selectors on included builds gradle/gradle#22335
• Use centralised repository definitions
• Rename subprojects to be more aligned.
• Convert 'examples' to included build, so that it can more easily depend on the 'core' projects
• Group Benchmarks runtime/generator/plugin repositories into a single included build
• Update Gradle to 8.8

[adam-enko]

This PR is no longer needed. Instead of splitting up the project, the Worker API was added in-place. It would be good to revisit this in the future though. Splitting out the generation code would improve code organisation, and prevent using compile-only dependencies in plugin config.