Allow FEEL shortcuts for FeelNumberField

[marstamm]

Is your feature request related to a problem? Please describe.

When using OptionalFeelNumberField, I want to enable it using the same keyboard shortcuts that I am used to (e.g. press = to enable the FEEL editor).

https://github.com/bpmn-io/properties-panel/blob/main/src/components/entries/FEEL/Feel.js#L318

Describe the solution you'd like

Same behavior as Text fields

Describe alternatives you've considered

None

Additional context

Discovered here: bpmn-io/bpmn-js-element-templates#64 (comment)

[nikku]

Moving to backlog for the time being.