Add `u{3000}` (a.k.a full-width space) to trimable characters.

[itsthomashere]

Summary
The character \u{3000} ( full-width space character) in utf8 encoding is considered trimable in javascript

Should we add this to timchars, would it be weird if JS trim it and this is not included?

[itsthomashere]

Also it seems to me from the comments that we it is intended for these to be trimmable right?

// white space characters
// https://en.wikipedia.org/wiki/Whitespace_character
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Character_Classes#Types
// \f\n\r\t\v\u00a0\u1680\u2000-\u200a\u2028\u2029\u202f\u205f\u3000\ufeff