Use _from_data instead of _from_columns for initialzing Frame

[mroeschke]

Description

In the spirit of reducing redundant methods, _from_columns just calls _from_data (hoping to rename to _from_mapping or similar) so removing the need for _from_columns.

Hoping to do the same for the _from_columns_like_self in a follow up.

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.

[isVoid]

A bit of background for _from_columns - this was introduced when we want to refactor the cython layer with only list of columns input and output. _from_columns was just a sugar to make constructing from the result of a cython function easier.

[mroeschke]

this was introduced when we want to refactor the cython layer with only list of columns input and output

Is this still an effort being worked on? My observation of the current usage is that it tends to always be paired with column labels like _from_data.

[isVoid]

If I remember correctly, the remaining work to be done are cuio cython APIs. But this work shouldn't be block by that, in fact, follow ups to that refactor can always resort to _from_data.

[mroeschke]

/merge

[vyasr]

this was introduced when we want to refactor the cython layer with only list of columns input and output

Is this still an effort being worked on? My observation of the current usage is that it tends to always be paired with column labels like _from_data.

This work was put on hold because I decided that getting pylibcudf done first would be better. Most of the structure that I imagined imposing at the Cython layer will be largely informed by refactoring cudf internals around pylibcudf objects once pylibcudf is done.