check_e_data() to allow an `id` or `ID` column

[francisbarton]

This makes it more compatible with data produced by DataHoover::dh_get_data().

[ThomUK]

Yes, I'd like to coerce everything to lowercase internally. A sloppy early design decision on my part.

[ThomUK]

Implementation Plan

Update check_e_data() to accept an id or ID column alongside the existing required columns, improving compatibility with data produced by DataHoover::dh_get_data().

Approach:

• In checking_functions.R, add "id" and "ID" to the list of columns that check_e_data() considers non-error (currently via check_for_required_columns() which fails on unknown columns — but actually the issue is that the function should silently tolerate extra columns; verify whether the current code passes through extra columns or strips them)
• If extra columns cause a downstream error, add a dplyr::select(any_of(...)) step to keep only the columns that downstream code needs
• Normalise: add a step to rename ID → id for consistency

Tests:

• check_e_data() with an id column does not error
• check_e_data() with an ID column does not error
• The returned data frame still contains the expected columns