fix(rollup): properly include dependencies

[tivac]

Description

Instead of injecting import statements use this.addWatchFile(<file>) like rollup intended.

Motivation and Context

Solves some weird chunking issues I was seeing and is generally way more correct across the board.

How Has This Been Tested?

Existing tests around chunking and watching still pass.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[codecov]

Codecov Report

Merging #602 into master will not change coverage.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master     #602   +/-   ##
=======================================
  Coverage   98.92%   98.92%           
=======================================
  Files          48       48           
  Lines        1211     1211           
  Branches      184      184           
=======================================
  Hits         1198     1198           
  Misses         13       13

Impacted Files	Coverage Δ
packages/rollup/rollup.js	100% <100%> (ø)	⬆️

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