Sorting milestones "numerically"

We discussed this previously. Our milestones are texts, so when you sort in ascending order you will see 11.10 before 11.2, 11.3, 11.4, etc. Is there a way to treat these "numerically" so that 11.10 is after 11.9?

Here's an example: https://gitlab.biterg.io/goto/af646257397acf06f344f19c65c5f929

In addition, is there a way to remove the "Others" column from the chart above?