Previously UriComponentsBuilder used a regular expression for parsing
query name-value pairs where both name and value were expected to not
contain neither '&', not '='. The idea is that the presence of reserved
characters makes it impossible to guess correctly how to parse the
query string (e.g. a=b&c).
This change relaxes the constraint on query param values, allowing them
to contain '='. In effect '&' is the ultimate separator of name-value
pairs, and any '=' in values is ignored. For example "q=1USD=?EUR" is
interpreted as "q equals '1USD=?EUR'".
Issue: SPR-9832
88906d271b