Spacers are off in RTL mode

[reckart]

Describe the bug In the brat visualizer, there are blank areas user at the start/end of rows and in between rows to help make the selection less jumpy. These work well in LTR mode but are somewhat off in RTL mode, in particular when the width of the svg is wider than the width of the surrounding div (i.e. horizontal scrolling).

To Reproduce Steps to reproduce the behavior:

1. Open a file with RTL script text
2. Create a very long annotation
3. Reduce the browser width if necessary to trigger a horizontal scrollbar
4. Inspect the SVG using the browser dom inspector and see where the row-initial, row-final spacers and the inter-row spacers are drawn.

Expected behavior The spacers should be fully contained in the SVG boundaries and they should be covered the full leading/trailing space in a row as well as inter-row space.

Please complete the following information:

• Version and build ID: 21.0.1