Add validation feature for patterns only

[willosborne]

This adds a simple validation mode that checks the provided pattern is valid JSON Schema; this isn't perfect but it gives us some guarantees.

Addresses issue #73 and #317

[willosborne]

This is a good first cut, but I think we can improve upon this later - e.g. running with -v shows loads of 'strict mode' errors that could be useful here:

debug:   Pattern Instantiation was not provided, only the JSON Schema will be validated
strict mode: unknown keyword: "defs"
strict mode: unknown keyword: "defs"
strict mode: required property "deployed-in" is not defined at "https://raw.githubusercontent.com/finos/architecture-as-code/main/calm/draft/2024-04/meta/core.json#/properties/relationship-type/oneOf/0" (strictRequired)
strict mode: required property "composed-of" is not defined at "https://raw.githubusercontent.com/finos/architecture-as-code/main/calm/draft/2024-04/meta/core.json#/properties/relationship-type/oneOf/1" (strictRequired)
strict mode: required property "interacts" is not defined at "https://raw.githubusercontent.com/finos/architecture-as-code/main/calm/draft/2024-04/meta/core.json#/properties/relationship-type/oneOf/2" (strictRequired)
strict mode: required property "connects" is not defined at "https://raw.githubusercontent.com/finos/architecture-as-code/main/calm/draft/2024-04/meta/core.json#/properties/relationship-type/oneOf/3" (strictRequired)
strict mode: "prefixItems" is 4-tuple, but minItems or maxItems/items are not specified or different at path "#/properties/nodes"
strict mode: missing type "object" for keyword "required" at "https://raw.githubusercontent.com/finos/architecture-as-code/main/calm/pattern/api-gateway#/properties/nodes/prefixItems/0" (strictTypes)
strict mode: missing type "object" for keyword "properties" at "https://raw.githubusercontent.com/finos/architecture-as-code/main/calm/pattern/api-gateway#/properties/nodes/prefixItems/0" (strictTypes)
strict mode: missing type "object" for keyword "properties" at "https://raw.githubusercontent.com/finos/architecture-as-code/main/calm/pattern/api-gateway#/properties/nodes/prefixItems/1" (strictTypes)
strict mode: missing type "object" for keyword "required" at "https://raw.githubusercontent.com/finos/architecture-as-code/main/calm/pattern/api-gateway#/properties/nodes/prefixItems/2" (strictTypes)
strict mode: missing type "object" for keyword "properties" at "https://raw.githubusercontent.com/finos/architecture-as-code/main/calm/pattern/api-gateway#/properties/nodes/prefixItems/2" (strictTypes)
strict mode: missing type "object" for keyword "properties" at "https://raw.githubusercontent.com/finos/architecture-as-code/main/calm/pattern/api-gateway#/properties/nodes/prefixItems/3" (strictTypes)
strict mode: "prefixItems" is 3-tuple, but minItems or maxItems/items are not specified or different at path "#/properties/relationships"
strict mode: missing type "object" for keyword "properties" at "https://raw.githubusercontent.com/finos/architecture-as-code/main/calm/pattern/api-gateway#/properties/relationships/prefixItems/0" (strictTypes)
strict mode: required property "deployed-in" is not defined at "https://raw.githubusercontent.com/finos/architecture-as-code/main/calm/draft/2024-04/meta/core.json#/properties/relationship-type/oneOf/0" (strictRequired)
strict mode: required property "composed-of" is not defined at "https://raw.githubusercontent.com/finos/architecture-as-code/main/calm/draft/2024-04/meta/core.json#/properties/relationship-type/oneOf/1" (strictRequired)
strict mode: required property "interacts" is not defined at "https://raw.githubusercontent.com/finos/architecture-as-code/main/calm/draft/2024-04/meta/core.json#/properties/relationship-type/oneOf/2" (strictRequired)
strict mode: required property "connects" is not defined at "https://raw.githubusercontent.com/finos/architecture-as-code/main/calm/draft/2024-04/meta/core.json#/properties/relationship-type/oneOf/3" (strictRequired)
strict mode: missing type "object" for keyword "properties" at "https://raw.githubusercontent.com/finos/architecture-as-code/main/calm/pattern/api-gateway#/properties/relationships/prefixItems/1" (strictTypes)
strict mode: missing type "object" for keyword "properties" at "https://raw.githubusercontent.com/finos/architecture-as-code/main/calm/pattern/api-gateway#/properties/relationships/prefixItems/2" (strictTypes)
info:    The JSON Schema is valid