Convenience functions for HAL _embedded and _links parsing

[gernot-h]

One of the main reasons for starting my OO API in #14+ was the constant, repetitive effort for parsing the ["_embedded"] and ["_links"] parts of the JSON answers. Last years have however shown that I don't find the time to finish the OO API, let alone the ongoing effort to maintain it.

With the help of qwen and Claude, I pulled out the ["_links"] and ["_embedded"] handling from my OO branch #14 into a thin extension of the sw360python API.

First of all, there are two new helper functions:

>>> rel = client.get_release("064123")
>>> client.get_linked_id(rel, "self")
064123
>>> client.get_linked_id(rel, "sw360:component")
184123
>>> client.get_embedded(rel, "sw360:attachments")
[{'filename': 'CLIXML_libgcrypt-2.0.xml',
  'attachmentType': 'COMPONENT_LICENSE_INFO_XML',
  '_links': {'self': {'href': 'https://sw360.siemens.com/resource/api/attachments/18f123'}}},
 {'filename': 'libgcrypt-2.0.tar.bz2',
  'attachmentType': 'SOURCE_SELF',
  '_links': {'self': {'href': 'https://sw360.siemens.com/resource/api/attachments/7a7123'}}},
  ...

The more intersting part is that it adds a new class SW360Response which is now always returned instead of the raw JSON objects. It's derived from dict and thus it should be 100% backward compatible. You can access everything in the JSON answer as before, but you can also use it in a much friendlier way.

The current way to get a component to a release rel still works:

client.get_component(client.get_id_from_href(rel["_links"]["sw360:component"]["href"])

But with the new code, you can also just do:

client.get_component(rel.linked_id("component"))

Or to get from a component to a release ID, the old way still works:

client.get_id_from_href(comp["_embedded"]["sw360:releases"][0]["_links"]["self"]["href"])

But you can now also use the new methods:

comp.embedded_list("releases")[0].linked_id()

@tngraf, let me know what you think!