Fix descriptions in the Table sample

[sukhova]

Table actions tab:

Replace phrase: The Table component implements ActionsHolder interface and can contain custom actions, as well as standard actions, defined in ListActionType enumeration.

with phrase

The Table component implements the ActionsHolder interface and can contain custom actions, as well as standard actions.

since the ListActionType enum does not exist

Editable table tab:

Replace phrase: (or ComboBox, if optionsDataContainer is additionally specified for the column)

with phrase

(or ComboBox, if optionsContainer is additionally specified for the column)

since the optionsDataContainer attribute does not exist

Table with icons provider tab:

Is the Table.IconProvider exist? I didn't find one.

Table with generated columns tab:

The phrase

The generator attribute specifies the name of the method that is called to create a generated column. The method receives an instance of the entity displayed in the corresponding row.

should be removed (https://github.com/Haulmont/jmix-ui/issues/569)

GroupTable tab:

Phrase A groupDataContainer must be specified for GroupTable in the dataContainer attribute of the rows element. contains outdated data.

Replace with

You should specify a data container of CollectionContainer type for GroupTable.