Adds nbsp highlighting for text matchers report

[Kutashov]

Overview

Currently, you can see errors like "expected: some string; was: some string" while working with strings that contain nbsp symbols. The reason being is an nsbp and a regular space-symbol are displayed equally. Apparently, this message looks confusing, it takes time to find out the root cause. It is even a bigger problem when there is multiple nbsp in string, debug time grows up dramatically.

Proposed Changes

I like the way the AS handles this, we can do it the same way.

[Kutashov]

@brettchabot Hi, there! Here is a copybara check, which got failed. Would you mind helping me, how could I fix this error?

[Kutashov]

@TWiStErRob Hi! Since we got no reply from @adazh for long time, shall we merge this version?

[TWiStErRob]

I'm not Google, just following the repo.

[adazh]

Sorry for the delay! Left a couple of comments.