Make most RunModule.runXxx commands exclusive

[lefou]

Fix #5208

[lefou]

This change breaks BSP support, since when we try to invoke the run command from an annonymous task, we get the error message:

Task.Anon@53839a78(mill.scalalib.bsp.BspRunModule.EmbeddableBspRunModule#internalBspRunModule.bspRun)
Non-exclusive task Task.Anon@53839a78(mill.scalalib.bsp.BspRunModule.EmbeddableBspRunModule#internalBspRunModule.bspRun) 
cannot depend on exclusive task app.run

[lefou]

That also means, BSP will always break if users have exclusive=true run-tasks. Ideally, we handle the exclusive flag differently when running from BSP.

[lihaoyi]

One option is to do what we did with bspClean, which is avoid depending on the exclusive def clean command and instead depend on a def cleanTask anonymous task. A similar refactor could be done for the def run commands to allow the anonymous task implementations to be used by BSP