feat(python): minor improvement to auto-detection of ambiguous data orientation

[alexander-beedie]

Closes #6368.

Improves the likelihood of correct orient inference if that param is not explicitly supplied (at DataFrame init time) and the number of rows/cols makes the determination ambiguous.

Example / setup:

import polars as pl
pl.DataFrame( 
    data = [(1,2,"foo"),(2,3,"bar"),(3,4,"baz")], 
    columns = ["x","y","z"],
)

Before:

# shape: (3, 3)
# ┌──────┬──────┬──────┐
# │ x    ┆ y    ┆ z    │
# │ ---  ┆ ---  ┆ ---  │
# │ str  ┆ str  ┆ str  │
# ╞══════╪══════╪══════╡
# │ null ┆ null ┆ null │
# │ null ┆ null ┆ null │
# │ foo  ┆ bar  ┆ baz  │
# └──────┴──────┴──────┘

After:

# shape: (3, 3)
# ┌─────┬─────┬─────┐
# │ x   ┆ y   ┆ z   │
# │ --- ┆ --- ┆ --- │
# │ i64 ┆ i64 ┆ str │
# ╞═════╪═════╪═════╡
# │ 1   ┆ 2   ┆ foo │
# │ 2   ┆ 3   ┆ bar │
# │ 3   ┆ 4   ┆ baz │
# └─────┴─────┴─────┘

[alexander-beedie]

(Will resolve conflicts when I get back to my laptop later).

[alexander-beedie]

@ritchie46: resolved 👍