[expotools] Show which package(s) failed in the check-packages script (#4915)
[expotools] Show which package(s) failed in the check-packages script (#4915)

# Why

Closes #4765 

# How

Instead of counting failures, I'm adding names of failed packages to the array and then show them in script's summary.

# Test Plan

I've modified two local packages without rebuilding and ran the script. Works as expected 👌 

exponentjs/exponent,exponentjs/exponent,exponent/exponent,exponent/exponent,exponentjs/exponent,exponent/exponent,exponentjs/exponent,exponentjs/exponent,exponent/exponent,exponentjs/exponent,exponent/exponent,exponentjs/exponent,exponentjs/exponent,exponent/exponent,exponent/exponent,exponentjs/exponent,exponent/exponent,exponent/exponent