so we can have server.on("/foo", HTTP_GET | HTTP_POST,
[](AsyncWebServerRequest *request) {}) to handle multiple methods.
this also saves a bit memory, enums are stored in int, which is 32bit on
xtensa. since we only have 7 methods (plus HTTP_ANY for everything) we
only want 7 bit, so uint8_t is pretty sufficient.
* New - server.rewirte() to rewrite the request url with optional get parameters injection.
New - rewrite.setFilter() and handler.setFilter() to specify a filter callback for more control on when to include them.
New - static file handler can be set with Last-Modified header value to support Not-Modified (304) response instead of serving the actual file.
* Remove clearRewrites & clearHandlers from server.mplement server distractor to delete internal members. Fixed and improved gzip stats calculation.
