feat: add support for environment definitions

[v-alexmoraru]

Removes the environment workarounds and records new tests for the enabled commands.

[Copilot]

Pull request overview

This PR adds first-class support for Environment item definitions in Fabric CLI, removing prior Environment-specific import workarounds and updating recorded command tests to reflect the new behavior.

Changes:

• Simplifies import payload generation and import flow by removing Environment-only branching/patch logic.
• Enables Environment definition format handling and marks Environment as supported for export/import in command support config.
• Updates/records CLI test fixtures and VCR recordings (including new export coverage for Environment invalid output path).

Reviewed changes

Copilot reviewed 36 out of 59 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/test_commands/test_import.py	Removes Environment-specific assertion branching to align with unified import behavior.
tests/test_commands/conftest.py	Expands test parametrization to include Environment in supported import/export scenarios.
tests/test_commands/recordings/test_commands/test_mkdir/class_setup.yaml	Updates VCR recording metadata for mkdir test setup.
tests/test_commands/recordings/test_commands/test_import/class_setup.yaml	Updates VCR recording metadata and item listings for import test setup.
tests/test_commands/recordings/test_commands/test_import/test_import_update_existing_item_success[SparkJobDefinition].yaml	Updates VCR recording to reflect current API responses for import update flow.
tests/test_commands/recordings/test_commands/test_import/test_import_update_existing_item_success[Reflex].yaml	Updates VCR recording to reflect current API responses for import update flow.
tests/test_commands/recordings/test_commands/test_import/test_import_update_existing_item_success[MirroredDatabase].yaml	Updates VCR recording to reflect current API responses for import update flow.
tests/test_commands/recordings/test_commands/test_import/test_import_update_existing_item_success[Lakehouse].yaml	Updates VCR recording to reflect current API responses for import update flow.
tests/test_commands/recordings/test_commands/test_import/test_import_update_existing_item_success[KQLQueryset].yaml	Updates VCR recording to reflect current API responses for import update flow.
tests/test_commands/recordings/test_commands/test_import/test_import_update_existing_item_success[KQLDashboard].yaml	Updates VCR recording to reflect current API responses for import update flow.
tests/test_commands/recordings/test_commands/test_import/test_import_update_existing_item_success[DataPipeline].yaml	Updates VCR recording to reflect current API responses for import update flow.
tests/test_commands/recordings/test_commands/test_import/test_import_create_new_item_fail[Warehouse].yaml	Updates VCR recording to reflect current API responses for import create-fail scenario.
tests/test_commands/recordings/test_commands/test_import/test_import_create_new_item_fail[MLExperiment].yaml	Updates VCR recording to reflect current API responses for import create-fail scenario.
tests/test_commands/recordings/test_commands/test_get/class_setup.yaml	Updates VCR recording metadata for get test setup.
tests/test_commands/recordings/test_commands/test_export/test_export_item_invalid_output_path_failure[Environment].yaml	Adds a new recording covering Environment export invalid output path behavior.
tests/test_commands/recordings/test_commands/test_export/class_setup.yaml	Updates VCR recording metadata for export test setup.
src/fabric_cli/utils/fab_cmd_import_utils.py	Removes Environment-special payload logic; always builds standard definition payloads.
src/fabric_cli/core/fab_types.py	Adds Environment to definition_format_mapping default handling.
src/fabric_cli/core/fab_config/command_support.yaml	Adds Environment to export supported items list.
src/fabric_cli/commands/fs/impor/fab_fs_import_item.py	Removes Environment-special import create/update logic; uses standard create/updateDefinition path.
.changes/unreleased/added-20260417-105920.yaml	Adds release note entry for Environment definition support.

[ayeshurun]

What are the implications of moving to the definitions approach? with the current approach we are doing some manual stuff, and at the end publishing the environment.

Did we compare the end result of two approaches? Perhaps we should keep support somehow of these two

[ayeshurun]

same question as above.