[#8A1459CB237A11FC6965FC29EC16E26399A6E0FA]
Erase params
iterator erase(iterator pos) noexcept;
This function removes an element from the container.
All iterators that are equal to `pos` or come after are invalidated.
url u( "?first=John&last=Doe" );
params_encoded_ref::iterator it = u.encoded_params().erase( u.encoded_params().begin() );
assert( u.encoded_query() == "last=Doe" );
Linear in `this->url().encoded_query().size()`.
Throws nothing.