Set 'ShowMandatory' to true on page controls for 'NotBlank' fields

[fvet]

When creating a new table (mainly to store referential data), we often set the NotBlank property to true to avoid insertion of blank values.

When creating an editable page (list / card) for this table, we mostly set the ShowMandatory property to true, to make it visible to the end user a value is expected for these field(s). The AL platform does not re-use the NotBlank to show a red '*' on pages (ShowMandatory), but only raises the error upon insert.

Expected rule:

• When a table field with NotBlank = true is used as a source expression for an editable page control, ShowMandatory must be set to true on the page control.