Parse Swift authentication headers case-insensitively

Also ensure they are added to the result object with the normalized
capitalization expected by downstream code.

Follow-up to 375cb207.
Revert "Parse Swift authentication headers case-insensitively"

Missing JIRA issue number.

This reverts commit e532e6f260c6070673ed9bb87294c4596e9e8b88.
JCLOUDS-656: Parse Swift authentication headers case-insensitively

Also ensure they are added to the result object with the normalized
capitalization expected by downstream code.

Follow-up to 375cb207.