Normalize schema sort orders

[cdmgtri]

In addition to sorting element and type declarations alphabetically in schemas, applying consistent sorting to additional parts of the schema will make content easier to find and to review across drafts or future releases.

• Sort namespace prefix declarations by prefix
• Sort import statements by target namespace
• Sort local terminology by term
• Sort type union members by qualified name
• Sort metadata appliesTo values by qualified name
• Sort components using case-insensitive order
• Sort facets by style (alphabetically with the exception of sorting min facets before max facets), value, and definition