NetServices: format code using `haiku-format`

This commit formats all the netservices2 code with the `haiku-format` tool from
https://github.com/owenca/haiku-format (commit aa7408e), with the following
customizations:
* SpaceBeforeRangeBasedForLoopColon is set to false
* Braces before a catch block are not wrapped
* Most headers, except for ExclusiveBorrow.h, have been manually reformatted
to adhere to Haiku's header format (issue #19 in the repository)

Change-Id: I693c4515cf26402e48f35d1213ab6d5fcf14bd1e

NetServices: add query part of the URL to the request

Change-Id: Ie169041925544f082a8be728d77cbc69edf2caa2

NetServices: Remove BHttpRequest::SerializeTo(BDataIO*)

The private version that serializes to a HttpBuffer is now used.

Change-Id: I034933a641e98b3a8f918470a024ba32ea7c8663

NetServices: add the HttpSerializer helper to help serialize requests

Change-Id: Ide1e2d387884ce4cf2d406057960cd0732d61f38

NetServices: Remove Accept as standard and protected header.

In the old service kit, the Accept header was automatically set. However, it is
not a required header. This removes the default value and the protection against
setting it manually.

Required to make HaikuDepot work.

Change-Id: Ic589bfc5829db25915b67f2a13b6c2436c053e25

NetServices: Add support for an input body in a request and handle this with redirects.

Change-Id: Id2399d49aa673469c8c04ebd13884cdbcb24112d

NetServices: Add/rework the MaxRedirections, Timeout and StopOnError options

Change-Id: I4e59b51c16c6777941dc92ce02505386257dad03

NetServices: Add support for Basic authentication

Change-Id: I304104f7096fd935212e1bfa3e988e7945cb5cec

NetServices: add optional fields to BHttpRequest

Change-Id: I6228419a55c81203ce2c26827d17ff6a402d86c5

NetServices: Implement BHttpStatusCode, BHttpStatusClass and Redirects

The user of the API can set whether redirects should be followed, and if so,
how many. This is part of the BHttpRequest API. The BHttpSession then follows
those instructions, and executes the maximum number of redirects the user
would like to follow.

As part of this commit, the BHttpStatusClass and BHttpStatusCodes helper enums
have been added, to give a friendlier access to HTTP status codes and status
classes.

Change-Id: Ic8c9e3fda158e2cce549c8f1d360951f7ac83311

NetServices: implement support for HEAD requests and 204 responses.

These particular responses will not have a body. This is now handled by the
BHttpSession object. There is also a minor fix in here that prevents a crash
when multiple requests are handled by the DataThread at the same time, and not
all of the requests have events.

Change-Id: I7f47d8b3cd8491c8193275be4b3fc1080780fa20

NetServices: Rewrite BHttpFields to use raw strings as underlying data storage

This change also drops the principle that fields with the same keys would be
grouped together. This was initially inspired by Boost::Beast, but it means a
lot of extra copying of data when adding/organizing the list, as well as
inefficient querying on each add. Now that the design choice is to fully go
for the raw string as underlying data storage, that choice is not necessary.
In the future it may be able to emulate the grouping or retrieving of lists
of values in the API, rather than as a fundamental principle of the data
storage.

Change-Id: I2667cfa38eb3b7b75393ee71fb038231a40b4193

NetServices: Serialize the header of a BHttpRequest to a string

Change-Id: Ib1e22536a0b39dc6e9461e7993ea6784f1ea0e2f

NetServices: implement hostname resolution and connection for BHttpRequest

BHttpSession::Execute() moves the request into the session, and returns a future BHttpResponse
object. Currently implemented are resolving the hostname, and opening the connection.

There is some scaffolding for the actual data transfer.

Change-Id: I5a8a7a7f8680036b91cdba4beee140bbed6bfd5a

NetServices: Introduce BHttpRequest class

Objects of this class describe a HTTP request. It contains several convenience
functions that will allow a user to describe the properties of the request.
More options to be added later.

Change-Id: If6a00d26808c5ed4b121cb36dc75a2a1cc449f95

NetServices: Add BHttpMethod that represents a HTTP method

This class provides defaults and performs basic validation for HTTP Methods as
defined by the standard. They will be used in conjunction with a future
BHttpRequest class.

Change-Id: If69a7ec186d9d1165e8efe5ab5df50d5a089208d