Stricter unicode space check in email regex (with tests)

[vesquen]

Fixes Or Enhances

Updates email regex which no longer allows the following Unicode spaces:
U+0020 Space (SP)
U+00A0 No-Break Space (NBSP)
U+1680 Ogham Space Mark
U+2000 En Quad
U+2001 Em Quad
U+2002 En Space
U+2003 Em Space
U+2004 Three-Per-Em Space
U+2005 Four-Per-Em Space
U+2006 Six-Per-Em Space
U+2007 Figure Space
U+2008 Punctuation Space
U+2009 Thin Space
U+200A Hair Space
U+2028 Line Separator
U+202F Narrow No-Break Space (NNBSP)
U+205F Medium Mathematical Space (MMSP)
U+3000 Ideographic Space

They are still allowed when between quotes in the local part.

Make sure that you've checked the boxes below before you submit PR:

• Tests exist or have been written that cover this particular change.

@go-playground/validator-maintainers

[coveralls]

coverage: 74.292% (+0.001%) from 74.291%
when pulling 5cdcd60 on Vesquen:stricter-unicode-space-check-in-email-regex
into a947377 on go-playground:master.