get_axis_labels() not working properly for rotated axis

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## Description of bug / unexpected behavior

get_axis_labels() is the function needed to add labels to the axes. It is not working properly when I rotated the axis.
This problem is especially prominent for:
1. Rotations not integer multiple of PI/2
2. Axis that has only positive direction

## Expected behavior

The labels should be near the tips of each axis.

## How to reproduce the issue

Case 1

```py
class GetAxisLabelsExample(Scene):
def construct(self):
ax = Axes(x_length=4, y_length=4).rotate(0.5*PI/2)
labels = ax.get_axis_labels(Tex("x"), Text("y"))
self.add(ax, labels)
```

Case 2

```py
class GetAxisLabelsExample(Scene):
def construct(self):
ax = Axes(x_length=4, y_length=4, x_range=[0, 12]).rotate(2*PI/2)
labels = ax.get_axis_labels(Tex("x"), Text("y"))
self.add(ax, labels)
```

## Additional media files

Case 1


Case 2


Start at Axes.get_axis_labels and run the two Python reproductions in the issue, comparing label placement after rotation and with x_range=[0, 12]. Done means both labels are positioned near their axis tips for arbitrary rotations and axes with only positive direction.

Written by the indexing model from the issue text.