refactor(set): refactor the update flow to construct PATCH request bodies correctly

[may-hartov]

Summary

Public Fabric APIs for updating resources (capacities, workspaces, items, etc.) are exposed as REST PATCH operations and expect request bodies to include only the fields being changed.
Our CLI set command previously fetched the full resource payload via GET, modified a single field (for example, displayName), and sent the entire object back to the update endpoint. This behavior does not align with PATCH semantics and can result in unexpected behavior or validation errors.
This PR refactors the update flow to construct PATCH request bodies correctly by extracting only the updated properties from the GET response.

Changes

• fab_cmd_set_utils:

  1. Extracted update_item_definition from update_fabric_element, as it is item-specific.
  2. Removed json_payload from update_fabric_element return values (unused by callers).
  3. Added extract_updated_only: bool = True to update_fabric_element to control whether only the updated path is extracted or the full payload is returned. For OneLake shortcut updates, this flag is set to False, since shortcuts use the Create API rather than an Update API.
  4. Introduced update_cache to reduce code duplication across fab_fs_set_* implementations.

• fab_fs_set_*
  Removed data.pop(...) calls. Since the payload now includes only the target path being updated, fields like id are no longer present and do not need to be stripped.

• fab_fs_set_connection
  Added connectivityType to the payload, as required by the Update Gateway API documentation.

• fab_fs_set_gateway
  Added the required type field, per the [Update Gateway API documentation.]((https://learn.microsoft.com/en-us/rest/api/fabric/core/connections/update-gateway).

Tests
Because this change affects how request payloads are constructed for update APIs, all set command tests were re-recorded to reflect the new behavior.

[Copilot]

Pull request overview

This PR refactors the set command implementation to properly align with REST PATCH semantics by sending only the updated properties rather than the entire resource payload. Previously, the CLI would fetch the full resource via GET, modify a single field, and send the entire object back via PATCH, which doesn't align with PATCH semantics and could cause validation errors.

Key changes:

• Extracted update_item_definition from update_fabric_element for item-specific base64 handling
• Added extract_updated_only parameter to control payload extraction behavior
• Introduced update_cache helper to reduce code duplication
• Updated tests to reflect new payload structure and cache behavior

Reviewed changes

Copilot reviewed 41 out of 45 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/fabric_cli/utils/fab_cmd_set_utils.py	Core refactoring: split item definition handling, added extract_updated_only flag, new update_cache helper
src/fabric_cli/errors/common.py	Added gateway-specific error messages for unsupported operations
tests/test_utils/test_fab_cmd_set_utils.py	Added test for update_item_definition, updated assertions for extracted properties
tests/test_commands/test_set.py	Updated cache assertion logic to only expect cache updates for displayName or name changes
tests/test_commands/recordings/**/*.yaml	Re-recorded VCR tests showing minimal PATCH payloads instead of full resource objects
tests/test_commands/api_processors/capacities_api_processor.py	Added defensive checks for optional fields in request/response handling
.changes/unreleased/optimization-20260101-115402.yaml	Changelog entry for the optimization