Only build one dist bundle with a flag for sub-actions

[kzantow]

Due to limitations of ncc, it is not possible to code split the bundles generated in dist/ but instead we are duplicating all the code in 3 separate bundles for the sub-actions. This is not particularly fast when committing and requires users to download a small amount more every time the action is used. The other option we have is just build a single bundle and switch based on some incoming parameter; this was done in the scan-action and works well. I think it is a preferable approach we should apply here.