Class: TEgFireGridColumnTitle
property Caption: string;The text of the title. It may contain <br>
markers, for a line break, and <var>Name</var>
markers, answered by OnGetVariableValue;
an empty caption shows no text.
It is set to the field’s DisplayLabel (its name when it
has none) the first time the column gets a FieldName
while the caption is empty; a caption set afterwards replaces it. An OnBeforeDrawTitle
handler can show another text without changing the caption.