WIP
Fix for #6300 - New validator takes into account non-Latin script numbers, exponential notation, and a few "look-alike" characters (space for NO_BREAK SPACE, comma for ARABIC DECIMAL SEPARATOR, and single quote for ARABIC THOUSANDS SEPARATOR).
Revert NumberFormat filter logic; Deal with decimal vs. scientific formatters; Move to prefix/suffix logic due to locales like mr; Remove LRM from string and symbols
Get more data on failed tests
Taking ICU4.x oddities into account (very large exponential symbols, missing grouping sizes for some locales)
Change to proper preg_quote instead of quotemeta
Add second parameter to preg_quote. Not needed, but good code practice anyways.
Check a float with lots of significant digits. This broke the old validator, but this validator correctly passes it for all locales.
[#6373] Reviewed for CS

- Concatenators should be on following line
- `||`/`&&` should be on following line
- Spaces around `.` concatenation
- Trailing whitespace
Merge branch 'hotfix/6373'

Close #6373
Fixes #6300