review Rights field and display

[evanwill]

• some rights seem to be trying to use Markdown formatting (e.g. spec email). avoid doing this for better interoperability of metadata.
• ensure rights statements make sense across all collections
• since search index ingests "rightsstatement" field in attempt to provide facet of rights (e.g. usecase: I want to search public domain images), ensure rightsstatement fields are correct, consistent, and mapped correct in config-search-index across collections
• check specific collection issues (e.g. plcphotos)