mod_ratelimit: Don't interfere with "chunked" encoding.
By the time ap_http_header_filter() sends the header brigade and adds the "CHUNK" filter, we need to garantee that the header went through all the filters' stack, and more specifically above ap_http_chunk_filter() which assumes that all it receives is content data. Since rate_limit_filter() may retain the header brigade, make it run after ap_http_chunk_filter(), just before AP_FTYPE_CONNECTION filters.
Also, ap_http_header_filter() shouldn't eat the EOS for HEAD/no-body responses. For instance mod_ratelimit depends on it since r1835168, but any next request filter may as well to flush and/or bail out approprietely.
This fixes the regression introduced in 2.4.34 (r1835168). PR 62568.
Submitted by: ylavic Reviewed by: covener, ylavic, jim