Subscriptions API Hosting Support for Sentinel Hub

[asonnenschein]

Related Issue(s):

Closes # Internal DND-879

Proposed Changes:

For inclusion in changelog (if applicable):

1. Support Subscriptions API hosting block for Sentinel Hub.

Not intended for changelog:

Diff of User Interface

Old behavior:

• Delivery block is required and hosting block is not supported.

New behavior:

• CLI and Python SDK both support specifying a hosting block, and delivery block is no longer required.

PR Checklist:

• This PR is as small and focused as possible
• If this PR includes proposed changes for inclusion in the changelog, the title of this PR summarizes those changes and is ready for inclusion in the Changelog.
• I have updated docstrings for function changes and docs in the 'docs' folder for user interface / behavior changes
• This PR does not break any examples or I have updated them

(Optional) @mentions for Notifications: