Fix RTL issues

[tomivirkki]

• Frozen translate direction
• Sort arrows should have space on the other side also
• Multi-sort indicator is on the wrong side
• Tree toggle arrow faces wrong direction
• Column borders variant places the borders on the wrong side

[JonUihlein]

Hello. Apologies if this is the wrong place to report additional RTL inconsistencies, but I believe there is also an issue with <vaadin-grid-selection-column> when setting frozen to true when direction is RTL. The column seems to be hidden behind other columns. Could be an issue with frozen columns in general.