Consider refactoring Table to support prop spreading on table cells

[greg-a-smith]

Prop spreading was added to Table for the header, body, header row and body rows. However, the current API does not easily support prop spreading to table cells (either <td> or <th>).

[jbadan]

Rework into separate subcomponents - see List: https://github.com/SAP/fundamental-react/tree/master/src/List

ie:

<Table>
   <Table.Header>...
  <Table.Body> ....
</Table>

[jbadan]

Related to https://github.com/SAP/fundamental-react/issues/969