Revert "[EzPublishLegacyBundle] renamed LegacyResponse::setHeaders() to LegacyResponse::setLegacyHeaders()"

This reverts commit 019db34b1e67d04d8b509bf3aa245f3b42a06a0e.
Revert "[eZPublishLegacyBundle] refactored the LegacyResponseManager to move some code into the LegacyResponse class where it is more appropriate."

This reverts commit 4e8755d4012e52c01193ae5ed110d5b4c5892381.

Conflicts:
	eZ/Bundle/EzPublishLegacyBundle/Tests/LegacyResponse/LegacyResponseManagerTest.php
Fix EZP-22414: Session is lost when redirecting from a legacy module

Avoid duplicate location headers
Merge pull request #802 from ezsystems/ezp-22414_duplicate_location_header_with_revert

Fix EZP-22414: Duplicate location header on legacy redirections