Layout a log message as a JSON hash, including MDC data

Changes for 0.60 - 2023-05-16

• Fix attempted use of non-hash references as hash references when using complex fields [github #10]
• Replace potentially unsave usages of each %hash with for loops

Data description and validation

Changes for 1.12

• Struct(..., -exclude => ..) returns richer error messages

Merges two users into the same effective user

Changes for 1.08 - 2023-05-16

• Cover merged user ids for ticket owner searches
• Cover merged user ids for ACL check in searches

data pack for Business::ISBN

Changes for 20230516.001 - 2023-05-16T15:09:45Z

• Data update for May 16, 2023

Map body and data parameters to a model

Changes for 0.017

• Allow a model to handle more than one content type