Improve output for cases when package build fails

[maxim-lobanov]

According to #137 and #78, tparse just writes build errors to stderr. Output example:

# github.com/***/***/internal/promotion
internal/promotion/***_test.go:17:42: expected ';', found testVar

With the current approach, it is super easy to miss such output and it is really complicated to find it by scrolling.
Also, stderr is written at the top of output. If you use --follow flag, you will get: stderr, then the full list of tests (which can be very very long), then summary about failed tests, then summary table. So, user has to scroll to the top to find build failure.

I propose to treat build failure as any other "failed test" error and print them before summary table:

--- BUILD ERROR: github.com/***/***/internal/promotion (0.00s)

    internal/promotion/***_test.go:17:42: 
                Error:          expected ';', found testVar

[maxim-lobanov]

I think this issue is follow up for 719b8a0
cc @mfridman