add file: dependency support for web frameworks

[austincrim]

Description

This PR re-introduces the ability to bundle and deploy a local dependency to Firebase Functions (when using web frameworks) by specifying the dependency version as file:./some-path.

If the specified path is a folder, it will run npm pack and copy the tarball into the deployed functions folder. If the specified path is a file, it will copy it directly to the functions folder.

[jamesdaniels]

Look into relative dirs and add a changelog, otherwise LGTM

[codecov-commenter]

Codecov Report

Base: 56.22% // Head: 56.18% // Decreases project coverage by -0.04% ⚠️

Coverage data is based on head (a790c47) compared to base (416d034).
Patch coverage: 5.88% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5440      +/-   ##
==========================================
- Coverage   56.22%   56.18%   -0.04%     
==========================================
  Files         317      317              
  Lines       21442    21457      +15     
  Branches     4376     4380       +4     
==========================================
  Hits        12056    12056              
- Misses       8326     8341      +15     
  Partials     1060     1060              

Impacted Files	Coverage Δ
src/emulator/storage/apis/shared.ts	9.09% <0.00%> (-0.59%)	⬇️
src/frameworks/index.ts	15.18% <7.14%> (-0.77%)	⬇️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.