Support querystrings in entrypoints and pass to plugins

[goosewobbler]

Working on an Electron project, looking to make Parcel use a single EJS entrypoint to compile (and serve) multiple HTML files. The current solution relies on specifying, e.g. for dev

parcel serve app/one.dev.html app/two.dev.html app/three.dev.html

These files are very similar, would benefit from templating, so I created an EJS template and was considering to use querystrings, updating the EJS transformer to pass them into the EJS compilation, e.g.

parcel serve app/dev.ejs?window=one app/dev.ejs?window=two app/dev.ejs?window=three

sarscode/parcel-transformer-ejs#11

However specifying querystrings on parcel entrypoints just seems to break compilation: #8543
https://github.com/parcel-bundler/parcel/blob/v2/packages/core/core/src/requests/EntryRequest.js#L180

Is there another way to do this? The only other way I thought of was to compile the the HTML files with EJS before pointing Parcel at them to serve / bundle, which seems like an unnecessary extra step.

Would be nice if Parcel would strip querystrings from entrypoints and pass them to transformers.