feat: add with_columns

[ion-elgreco]

Which issue does this PR close?

• closes Replace with_column with with_columns  #838
• related RFC: Re-work some DataFrame APIs #875

Rationale for this change

Gives more flexibility to the user.

What changes are included in this PR?

Adds a with_columns which is a wrapper around with_column in Rust, the schema_name of the expr is used as the name. However I think we could improve over this in a follow up, since we should keep the original name unless somewhere down the expr path alias was called.

See this example of Polars VS Datafusion now:

original df

+---+---+---+
| a | b | c |
+---+---+---+
| 1 | 4 | 8 |
| 2 | 5 | 5 |
| 3 | 6 | 8 |
+---+---+---+

Polars

df.with_columns(pl.col('a)+5)
┌─────┬─────┬─────┐
│ a   ┆ b   ┆ c   │
│ --- ┆ --- ┆ --- │
│ i64 ┆ i64 ┆ i64 │
╞═════╪═════╪═════╡
│ 6   ┆ 4   ┆ 8   │
│ 7   ┆ 5   ┆ 5   │
│ 8   ┆ 6   ┆ 8   │
└─────┴─────┴─────┘

Datafusion

df.with_columns(column('a')+5)
+---+---+---+--------------+
| a | b | c | a + Int64(5) |
+---+---+---+--------------+
| 1 | 4 | 8 | 6            |
| 2 | 5 | 5 | 7            |
| 3 | 6 | 8 | 8            |
+---+---+---+--------------+

Are there any user-facing changes?

Adds new with_columns method on DataFrame.

[timsaucer]

This is a great addition!

[timsaucer]

Do you know if this renders right in the online doc? If not, I can pull your branch and test it out

[ion-elgreco]

@timsaucer I am not sure, is it possible to locally build the docs?

[timsaucer]

Yes, there is a build script in the docs folder and then you can open the generated html files locally.