Package Kit: reduce identifer/base-url confusion

For historical reasons, the package kit has an "url" field that is not
actually meant to be used as an URL. Rename it in the API and user
facing output as "identifier" to make it clear what the file is used
for. This change preserves the "url" key in on-disk and online storage
(hpkr files, stored settings, etc) in an attempt to not break anything.

Fix one remaining misuse of the "url" field as an URL in
get_package_dependencies.

Add an unit test showing that BUrl does parse "tab" URIs properly (there
is just a protocol and a path segment).

Change-Id: I339ce526e5798d42d78ae650855d7e988dbb4a1a
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2542
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

BUrl: allow URLs without protocol or authority again.

Parsing an URL can never fail. The regexp is designed to match any
input. In the worst case, everything will end up in the "path"
component. WebPositive relies on this to generate file URLs from a plain
path.

URLs without a protocol are also possible, and can be used with an
implicit protocol. A typical example is network shares sometimes noted in
"//host.domain/path/file" form.

Add tests for these two cases and fix the parser to behave as expected.

BUrl: IDNA ToUnicode and ToASCII conversions.

* Since DNS are normally restricted to ASCII, the use of UTF-8 in domain
names is implemented using a "punycode" encoding.
* The request to the DNS server must be sent with the ASCII
representation of the domain name, however the Unicode one should be
used for user-visible parts.
* ICU provides an implementation of the conversion, which we use here.
* Conversion is currently done in-place and modifies the BUrl object
(this is similar to UrlEncode/UrlDecode).
* Adjust existing IDN test to make use of these methods. It's passing
now.

UrlTest: cleanup IDN tests.

Test for relative URL with a port in the base URL.

As expected, the port is preserved.

Add WizzNic

* Update sdl_image_x86 to a version that can load PNG files
* Update giflib_x86 to match what's required by the new SDL_image
package

Rename url directory to "service"

* All "services kit" tests will move there.

BUrl: IDNA ToUnicode and ToASCII conversions.

* Since DNS are normally restricted to ASCII, the use of UTF-8 in domain
names is implemented using a "punycode" encoding.
* The request to the DNS server must be sent with the ASCII
representation of the domain name, however the Unicode one should be
used for user-visible parts.
* ICU provides an implementation of the conversion, which we use here.
* Conversion is currently done in-place and modifies the BUrl object
(this is similar to UrlEncode/UrlDecode).
* Adjust existing IDN test to make use of these methods. It's passing
now.

UrlTest: cleanup IDN tests.

Test for relative URL with a port in the base URL.

As expected, the port is preserved.

Add WizzNic

* Update sdl_image_x86 to a version that can load PNG files
* Update giflib_x86 to match what's required by the new SDL_image
package

Rename url directory to "service"

* All "services kit" tests will move there.