This PR partially fixes a circular dependency problem whereby the
creation of a project queries Angular plugin for external files, but
the discovery of external files requires root files to be defined in a
Project. The right approach is to return empty array if Project has no
root files.
PR Close#32519
This PR removes `tsserverlibrary` from rollup globals since the symbol
should not appear by the time rollup is invoked. `tsserverlibrary` is
used for types only, so the import statement should not be emitted by
tsc.
PR Close#30123