Enable using dropdown menus for a datafield property on a custom shape

[chris-hampel-CA]

• I agree to follow the Code of Conduct that this project adheres to.
• I have searched the issue tracker for a feature request that matches the one I want to file, without success.

Is your feature request related to a problem? Please describe.
Feature request is not related to a problem with the tool, but its addition would make it easier to use in some situations

Describe the solution you'd like
When making custom shapes, after selecting Edit Data, a user can add property data with as many fields as they want. The data is always distinguished by a name, and a blank text box, which can contain any information, appears.

For my purposes, I seek to create a library of shapes for other users to make specific flowsheets. There are certain shapes where I would like one of the data fields to only be one selection from a predefined list of options. Rather than requiring the user to know what the set of options is and the exact valid name of each possible option, I would like to create a shape such that I can add the list of options displayed as a "dropdown menu" for the data field.

Describe alternatives you've considered

• Adding a tooltip message which contains the list of valid options to input to the datafield.
• Give the user an externally generated instruction manual that describes each shape. Adding too much detail in a tooltip message can be clunky.

Additional context
Add any other context or screenshots about the feature request here.