[Go][IPC] ipc.Writer corrupts null bitmaps in columns with offsets

[asfimport]

If a column has null values and an offset, the existing ipc.Writer implementation will fail to truncate the null bitmap and it will become misaligned with the truncated array data.

PR incoming.

Reporter: Chris Hoff / @chriscasola
Assignee: Chris Hoff / @chriscasola

PRs and other links:

• GitHub Pull Request #12278

_{Note: This issue was originally created as ARROW-15488. Please see the migration documentation for further details.}

[asfimport]

Matthew Topol / @zeroshade:
Issue resolved by pull request 12278
#12278