Function createDisplayName

Creates a human-readable display name from a database identifier. Handles:

• snake_case: "organization_email" -> "Organization Email"
• PascalCase/camelCase: "OrganizationEmail" -> "Organization Email"
• ALL CAPS: "PAYMENT" -> "Payment" (when normalizeAllCaps is true)
• ALL CAPS compound: "INDIVIDUALDESIGNATION" -> "Individual Designation" (when splitCompoundWords is true)

Snake_case identifiers are split on underscores and title-cased first, then fed through the existing camelCase logic to handle mixed conventions like "org_emailAddress" -> "Org Email Address".