This change brings Angular largely in line with how AngularJS previously serialized URLs. This is based on RFC 3986 and resolves issues such as the above #10280 where URLs could be parsed, re-serialized, then parsed again producing a different result on the second parsing.
Adjustments to be aware of in this commit:
* URI fragments will now serialize the same as query strings
* In the URI path or segments (portion prior to query string and/or fragment), the plus sign (`+`) and ampersand (`&`) will appear decoded
* In the URL path or segments, parentheses values (`(` and `)`) will now appear percent encoded as `%28` and `%29` respectively
* In the URL path or segments, semicolons will be encoded in their percent encoding `%3B`
NOTE: Parentheses and semicolons denoting auxillary routes or matrix params will still appear in their decoded form -- only parentheses and semicolons used as values in a segment or key/value pair for matrix params will be encoded.
While these changes are not considered breaking because applications should be decoding URLs and key/value pairs, it is possible that some unit tests will break if comparing hard-coded URLs in tests since that hard coded string will represent the old encoding. Therefore we are releasing this fix in the upcoming Angular v6 rather than adding it to a patch for v5.
Fixes: #10280
PR Close#22337