Fix misleading date spacing in player rank graphs

[abaisero]

Is your feature request related to a problem?

In the current rank graphs, the x-axis corresponds to dates but are spaced away uniformly from each other, rather than in accordance to the difference between dates, which warps the visualization of rank progress. While the data presented is technically correct (which is why I didn't submit this as a bug), it is a clear and obvious visualization flaw which needs to be fixed.

Describe the feature you'd like to see on the AGAGD.

In the player rank progress, either space the ticks away according to the time difference between dates, or (alternatively), perform some data interpolation in order to visualize dates which are actually uniform.

Notes

The following is a screenshot of one of the rank graphs (cut to maintain player anonymity), which shows equally-spaced ticks corresponding to different time periods (respectively, 1, 1, 4, 2, 1, 1, 5, and 2 months):