feat(rust/signed-doc): Proper CDDL schema processing

[Mr-Leshiy]

Description

Introduces a CDDL schema processing for Content validation rule.

Description of Changes

• Removed catalyst_signed_doc::validator::json_schema:: JsonSchema and replaced with the newly added catalyst_types::json_schema::JsonSchema.
• Update catalyst-signed-doc-spec, process CDDl definitions as well.
• Modified Content validation rule, added CDDL schema processing (without applying validation against CDDL schema).

Please confirm the following checks

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream module

[github-actions]

📚 Docs Preview

The docs for this PR can be previewed at the following URL:

https://docs.dev.projectcatalyst.io/libs/feat/cddl-schema

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 554/554}$ | ${\color{red}Fail: 0/554}$ |