Change the warnings that appear when the structure contains R-Groups/R-Sites/Attachment points

Background:
When there is R-Group/ R-Site/Attachment point in the structure the text of warnings is different for Remote and Standalone modes. In both modes these warnings are not completely correct:

_Remote_
'R-Groups warning: Structure contains RGroup components' - appears when R-Group/ R-Site/Attachment point is present on the canvas.

_Standalone_
'R-Groups warning: Structure contains R-groups' - appears when R-Group/R-Site/Attachment point is present on the canvas.

Acceptance criteria:
- 'R-Groups warning: Structure contains R-Groups' - appears only when R-Group is present on the canvas.
- 'R-Group features warning: Structure contains R-sites' – appears when R-site is present on the canvas.
- 'R-Group features warning: Structure contains Attachment points’ – appears when Attachment point is present on the canvas.
- If there are both R-Group and Attachment point in one structure only 'R-Groups warning: Structure contains R-Groups' appears.