Demisto-sdk

* **Note: Demisto-SDK will soon stop supporting Python 3.8**
* Fixed an issue where using **download** on non-unicode content, merging them into existing files caused an error.
* Changed an internal setting to allow writing non-ascii content (unicode) using `YAMLHandler` and `JSONHandler`.
* Fixed an issue where an error message in **unify** was unclear for invalid input.
* Fixed an issue where running **validate** failed with **is_valid_integration_file_path_in_folder** on integrations that use API modules.
* Fixed an issue where **validate** failed with **is_valid_integration_file_path_in_folder** on integrations that use the `MSAPIModule`.
* Added **validate** check for the `modules` field in `pack_metadata.json` files.
* Changed **lint** to skip deprecated content, unless when using the `-i` flag.
* Fixed an issue where **update-release-notes** failed when a new *Parsing Rule* was added to a pack.
* Refactored the logging framework. Demisto-SDK logs will now be written to `.demist_sdk_debug.log` under the content path (when detected) or the current directory.
* Added `GR105` validation to **validate** command to check that no duplicate IDs are used.
* Added support for API Modules imported in API modules in the **unify** command.
* Added **validate** check, to make sure every Python file has a corresponding unit test file.

* Fixed an issue where running **validate** with the `-g` flag would skip some validations for old-formatted (unified) integration/script files.
* Deprecated integrations and scripts will not run anymore when providing the **--all-packs** to the **lint** command.
* Fixed an issue where a pack `serverMinVersion` would be calculated by the minimal fromVersion of its content items.
* Added the `--docker-image-target` flag to **lint** for testing native supported content with new images.

* Fixed an issue where running **run-test-playbook** would not use the `verify` parameter correctly. ajoga
* Added a newline at the end of README files generated in **generate-docs**.
* Added the value `3` (out of bounds) to the `onChangeRepAlg` and `reputationCalc` fields under the `IncidentType` and `GenericType` schemas. **validate** will allow using it now.
* Fixed an issue where **doc-review** required dot suffixes in release notes describing new content.
* Fixed an issue where **validate** failed on Feed Integrations after adding the new *Collect/Connect* section field.
* Fixed an issue where using **postman-codegen** failed converting strings containing digits to kebab-case.
* Fixed an issue where the ***error-code*** command could not parse List[str] parameter.
* Updated validation *LO107* to support more section types in XSIAM layouts.

* Added support for running **lint** in multiple native-docker images.

* Fixed an issue where running **format** would fail after running npm install.
* Improved the graph validations in the **validate** command:
- GR100 will now run on all content items of changed packs.
- GR101 and GR102 will now catch invalid fromversion/toversion of files **using** the changed items.
- GR103 errors will raise a warning when using the *-a* flag, but an error if using the *-i* or *g* flags.
* Fixed an issue where test-playbooks timed out.
* Fixed an issue where making a change in a module using an ApiModule would cause lint to run on the ApiModule unnecessarily.
* Fixed an issue where the `marketplace` field was not used when dumping pack zips.
* Fixed a typo in the README content generated with **update-release-notes** for updating integrations.
* Fixed an issue in **validate**, where using the `-gr` and `-i` flags did not run properly.
* Added the `sectionorder` field to integration scheme.
* Fixed an issue where in some occasions running of test-playbooks could receive session timeouts.
* Fixed an issue where **validate** command failed on core pack dependencies validation because of test dependencies.

* Added markdown lint formatting for README files in the **format** command.
* Fixed an issue where **lint** failed when using the `-cdam` flag with changed dependant api modules.
* Fixed an issue in the **upload** command, where `json`-based content items were not unified correctly when using the `--zip` argument.
* Added XPANSE core packs validations.