Add Interface inlined JSONSchema validator

[mszostok]

Description

Changes proposed in this pull request:

• Add Interface inline JSONSchema validator
• Add unit-test coverage
• Refactor code, so the "core" logic is shared between functions

Testing

Implemented logic is covered with unit-test. To test it locally, run:

1. Checkout this branch and build CLI:

   gh pr checkout -R capactio/capact 550

   make build-tool-cli

2. Clone hub-manifests repo:

   gh repo clone capactio/hub-manifests

3. Execute manifest validate (without server-side):

   capact manifest validate {HUB_MANIFEST_REPO_PATH}/manifests/**/*.yaml

4. Introduce error in Interface JSONSchema:

   Change in /manifests/interface/capactio/capact/validation/action/update.yaml property type to e.g. hakuna-matata instead of string.

5. Execute validate once again:

   capact manifest validate {HUB_MANIFEST_REPO_PATH}/manifests/**/*.yaml
   Validating files in 5 concurrent jobs...
   - ✗ "./manifests/interface/capactio/capact/validation/action/update.yaml":
       * InterfaceValidator: properties.testString.type: Must validate at least one schema (anyOf)
       * InterfaceValidator: properties.testString.type: properties.testString.type must be one of the following: "array", "boolean", "integer", "null", "number", "object", "string"
   
   Validated 162 files in total.
   Error: detected 2 validation errors

Related issue(s)

• https://github.com/capactio/capact/issues/487