fix(sourcemaps) copy vendor.js.map

[HugoHeneault]

Short description of what this resolves:

Keep vendor.js.map instead of ignoring it

Changes proposed in this pull request:

• For unkown (and uncommented) reason, vendor.js.map was skipped on sourcemaps copy
• I removed this filtering

Fixes: # might partially fix #1235 (for the missing vendor part)

[imhoffd]

@HugoHeneault I think we excluded it by default in the beginning because the generated source map file is usually pretty large.

It may be better to have this behind an option?

[HugoHeneault]

@dwieeb Sure! If I remember right I think polyfill.js was also missing!