gh-35614: allow non-minimal equation for padic heights
### :books: Description
Fixes #34790
The `p`-adic height calculations on an elliptic curve assumed that the
equation was minimal.
This is fixed as well as some docstring formatting.
The main mathematical change is in padics.py, new line 579, which is
then used in new line 931. This makes sure that the point is multiplied
by an integer such that it has good reduction at all primes, even if the
model is not minimal. Though it is still assumed that the models is
integral.
The rest is cosmetics.
### :memo: Checklist
- `[x]` The title is concise, informative, and self-explanatory.
- `[x]` The description explains in detail what this PR is about.
- `[x]` I have linked a relevant issue or discussion.
- `[x]` I have created tests covering the changes.
- `[x]` I have updated the documentation accordingly.
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URL: https://github.com/sagemath/sage/pull/35614
Reported by: Chris Wuthrich
Reviewer(s): Chris Wuthrich, John Cremona
