Implement parser rules according RFC

[AlexanderMac]

• [x] Header list can be empty?
• [x] Header value can be empty?
• [x] Cookies list can be empty?
• [x] Header value can be empty?
• [x] Body can be empty:
  • when contentType is multipart
  • when contentType is url-form-encoded
  • other
• [x] #29 Find a way to process multipart/form-data requests with file parameters

RFC

• https://tools.ietf.org/html/rfc7230, Hypertext Transfer Protocol (HTTP/1.1)
• https://tools.ietf.org/html/rfc7578 and https://tools.ietf.org/html/rfc2183, multipart/form-data

Syntax Notation

• https://tools.ietf.org/html/rfc5234
• https://tools.ietf.org/html/rfc5234#appendix-B.1
• https://tools.ietf.org/html/rfc7230#section-1.2

Rules

ALPHA   =  %x41-5A / %x61-7A; A-Z / a-z
BIT     =  "0" / "1"
CHAR    =  %x01-7F; any 7-bit US-ASCII character, excluding NUL
CR      =  %x0D; carriage return
CRLF    =  CR LF; Internet standard newline
CTL     =  %x00-1F / %x7F; controls
DIGIT   =  %x30-39; 0-9
DQUOTE  =  %x22; " (Double Quote)
HEXDIG  =  DIGIT / "A" / "B" / "C" / "D" / "E" / "F"
HTAB    =  %x09; horizontal tab
LF      =  %x0A; linefeed
LWSP    =  *(WSP / CRLF WSP)
           ; Use of this linear-white-space rule
           ;  permits lines containing only white
           ;  space that are no longer legal in
           ;  mail headers and have caused
           ;  interoperability problems in other
           ;  contexts.
           ; Do not use when defining mail
           ;  headers and use with caution in
           ;  other contexts.
OCTET   =  %x00-FF; 8 bits of data
SP      =  %x20
VCHAR   =  %x21-7E; visible (printing) characters
WSP     =  SP / HTAB; white space

OWS     = *( SP / HTAB ); optional whitespace
RWS     = 1*( SP / HTAB ); required whitespace
BWS     = OWS; "bad" whitespace

[AlexanderMac]

Done.