Allow for metadata to be added to change history (supporting workflow bot changes)

[nigel-bmlt]

Tracking issue Re older thread: https://bmlt.slack.com/archives/C11N1P0J0/p1646516933789499

Intent is to allow for some metadata to be added when a change is submitted, with the intent of allowing third party interactors (like the workflow plugin) to add information about the change such as the originating user.

[nigel-bmlt]

Have looked through the change schema and it appears 'change_description_text'(defined as SQL text type) is not used but is stored away on db read via $this->SetLocalDescription on a c_comdef_change object.

Would it be a valid use of this column to use it to store a free text change metadata value? It would save a schema update, but I'm not sure of the original intention of the column.

[nigel-bmlt]

is this something we could add into the 3.x admin api as part of meeting api endpoint - make it an optional field for create and update calls

[jbraswell]

Possibly. I want to get 3.x out without any new features first, and then consider stuff like this once folks have started upgrading and we are confident we are stable.