V0.18.1 NumberLine's number_to_point() is broken when using `add_tip`

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## Description of bug / unexpected behavior
the method `.number_to_point()` does not provide the correct position in scene coordinates

## Expected behavior
...well, it should provide the correct location along the numberline

## How to reproduce the issue
Code for reproducing the problem

```py
class group2(Scene):
def construct(self):
axes = NumberLine(x_range=[-5,5.2,1]).add_numbers().add_tip(tip_length=0.5,tip_width=0.1)
t = [MathTex("h_{i}") for i in range(1,11)]
self.add(axes)
for i in range(1,10):
self.add(t[i].next_to(axes.n2p(i-6),DOWN,buff=0.5))
self.add(Dot().move_to(axes.n2p(i-6)))
```

Without the added tip, the positions are correct

```py
class group2(Scene):
def construct(self):
axes = NumberLine(
x_range=[-5,5.2,1]).add_numbers()
t = [MathTex("h_{i}") for i in range(1,11)]
self.add(axes)
for i in range(1,10):
self.add(t[i].next_to(axes.n2p(i-6),DOWN,buff=0.5))
self.add(Dot().move_to(axes.n2p(i-6)))
```

Also adding the tip from the start works

```py
class group2(Scene):
def construct(self):
axes = NumberLine(
x_range=[-5,5.5,1],
include_tip=True,
).add_numbers()
t = [MathTex("h_{i}") for i in range(1,11)]
self.add(axes)
for i in range(1,10):
self.add(t[i].next_to(axes.n2p(i-6),DOWN,buff=0.5))
self.add(Dot().move_to(axes.n2p(i-6)))
```

## Additional media files
Images/GIFs




## System specifications

System Details

- OS (with version, e.g., Windows 10 v2004 or macOS 10.15 (Catalina)): Windows 10 64 bit
- Python version (`python/py/python3 --version`): 3.11.6

## Additional comments

Start at NumberLine.number_to_point() and compare the provided reproductions where add_tip() is called after construction versus include_tip=True at initialization. Run the example scene and verify that points returned by number_to_point() remain at the correct scene coordinates when a tip is added.

Written by the indexing model from the issue text.