Update content request handling to not use just any reserved location

[bjester]

Observed behavior

When a Kolibri has content requests that need processing, it may attempt to download content from KDP, now that KDP is included as a reserved network location, similarly to Studio. Originally, Studio was the only reserved location when the automatic content import feature was released.

[python-devserver] INFO     2024-11-22 10:05:42,385 Attempting connection to: https://kolibridataportal.learningequality.org/
[python-devserver] DEBUG    2024-11-22 10:05:42,387 Starting new HTTPS connection (1): kolibridataportal.learningequality.org:443
[python-devserver] DEBUG    2024-11-22 10:05:42,622 [https://kolibridataportal.learningequality.org:443](https://kolibridataportal.learningequality.org/) "GET /api/public/info/?v=3 HTTP/1.1" 200 None
[python-devserver] ERROR    2024-11-22 10:05:42,623 Server is not running Kolibri or Studio
[python-devserver] Traceback (most recent call last):
[python-devserver]   File "/home/richard/github/kolibri/kolibri/core/content/utils/content_request.py", line 816, in _process_download
[python-devserver]     import_manager = ContentDownloadRequestResourceImportManager(
[python-devserver]   File "/home/richard/github/kolibri/kolibri/core/content/utils/resource_import.py", line 560, in __init__
[python-devserver]     super(ContentDownloadRequestResourceImportManager, self).__init__(
[python-devserver]   File "/home/richard/github/kolibri/kolibri/core/content/utils/resource_import.py", line 390, in __init__
[python-devserver]     self.public = lookup_channel_listing_status(
[python-devserver]   File "/home/richard/github/kolibri/kolibri/core/content/utils/resource_import.py", line 46, in lookup_channel_listing_status
[python-devserver]     client = NetworkClient.build_for_address(baseurl)
[python-devserver]   File "/home/richard/github/kolibri/kolibri/core/discovery/utils/network/client.py", line 83, in build_for_address
[python-devserver]     if client.connect(raise_if_unavailable=False):
[python-devserver]   File "/home/richard/github/kolibri/kolibri/core/discovery/utils/network/client.py", line 218, in connect
[python-devserver]     raise errors.NetworkLocationInvalidResponse(
[python-devserver] kolibri.core.discovery.utils.network.errors.NetworkLocationInvalidResponse: Server is not running Kolibri or Studio

Desired behavior

This check intends to allow Studio to be used for content import. Since that's its intent, we should just make it explicit so it avoids picking up KDP, and only bypasses the connection check if the location represents Studio.