Converge all messages into a common format strings object

[michaelcfanning]

rule.messages would be a dictionary from id to an object which contains various format strings, currently covering plaintext and markdown only (plaintext is required). In future, other formats could fill out this object.

[michaelcfanning]

'run.richTextMessageMimeType' renamed to 'run.markdownMessageMimeType'.
'message.richText' renamed to 'message.markdown'.
'message.richMessageId' deleted.
Create 'multiformatMessageString' object, that holds plain text and markdown message format strings.
'reportingDescriptor.messageStrings' is now a dictionary of these objects, keyed by message id.
'reporting.Descriptor.richMessageStrings' dictionary is deleted.
'toolComponent.globalMessageStrings' now a dictionary of string to multiformat message strings.

[michaelcfanning]

This change has been accepted into the 01-24 schema + SDK

[ghost]

E-BALLOT 3 PROPOSAL

• Define a multiformatMessageString object with the following properties:
  • text of type string, non-empty, required.
  • markdown of type string, non-empty, optional.
• In the resource object (it's still there because this is written before Remove current localization mechanism #325):
  • Change the type of the messageStrings property from object with string-valued properties to object with multiformatMessageString-valued properties.
• In the rule object (it's still there because this is written before Provide full metadata objects for notifications #311):
  • Change the type of the messageStrings property from object with string-valued properties to object with multiformatMessageString-valued properties.
  • Change the type of the help property from string to multiformatMessageString.
  • Remove the richMessageStrings property.
  • Change the type of the help property from message to multiformatMessageString.
• In the message object:
  • Rename the richText property to markdown.
  • Remove the richMessageId property.
• In the run object:
  • Remove the richMessageMimeType property.

[ghost]

Approved in e-ballot-3.