[BUG] default serialization changed and parameter not respected

[line-o]

Describe the bug

Starting with exist-db 7.0.0-SNAPSHOT documents that are serialised to XML (at least over XML-RPC) do no longer respect the omit-xml-declaration option.

Before, setting it to 'yes' did omit the declaration and this is also the default behaviour in all released versions.

Expected behavior

The XML-RPC API to continue to respect serialization settings.

To Reproduce

If the above isn't working, please tell us the exact steps you took when you encountered the problem:

1. Request any XML document over XML-RPC

2. It will have an XML declaration at the beginning

3. Request any XML document over XML-RPC and set omit-xml-declaration to yes

4. It will have an XML declaration at the beginning

Context (please always complete the following information)

• Build: eXist-7.0.0-SNAPSHOT (b032a42)
• Java: 17.0.6 (Azul Systems, Inc.)
• OS: Mac OS X 13.5.2 (aarch64)

Additional context

• How is eXist-db installed? docker image
• Any custom changes in e.g. conf.xml? none

[line-o]

Relevant Test output from node-exist

# serialized with default options
not ok 47 file was read
  ---
    operator: equal
    expected: |-
      '<collection>\n    <item property="value"/>\n</collection>'
    actual: |-
      '<?xml version="1.0" encoding="UTF-8"?>\n<collection>\n    <item property="value"/>\n</collection>'
    at: Test.<anonymous> (/home/runner/work/node-exist/node-exist/spec/tests/documents.js:84:10)
    stack: |-
      Error: file was read
          at Test.assert [as _assert] (/home/runner/work/node-exist/node-exist/node_modules/tape/lib/test.js:312:48)
          at Test.bound [as _assert] (/home/runner/work/node-exist/node-exist/node_modules/tape/lib/test.js:95:17)
          at Test.strictEqual (/home/runner/work/node-exist/node-exist/node_modules/tape/lib/test.js:476:7)
          at Test.bound [as equal] (/home/runner/work/node-exist/node-exist/node_modules/tape/lib/test.js:95:17)
          at Test.<anonymous> (/home/runner/work/node-exist/node-exist/spec/tests/documents.js:84:10)
          at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
  ...
# serialized without XML declaration
not ok 48 expected file contents received
  ---
    operator: equal
    expected: |-
      '<collection>\n    <item property="value"/>\n</collection>'
    actual: |-
      '<?xml version="1.0" encoding="UTF-8"?>\n<collection>\n    <item property="value"/>\n</collection>'
    at: Test.<anonymous> (/home/runner/work/node-exist/node-exist/spec/tests/documents.js:102:10)
    stack: |-
      Error: expected file contents received
          at Test.assert [as _assert] (/home/runner/work/node-exist/node-exist/node_modules/tape/lib/test.js:312:48)
          at Test.bound [as _assert] (/home/runner/work/node-exist/node-exist/node_modules/tape/lib/test.js:95:17)
          at Test.strictEqual (/home/runner/work/node-exist/node-exist/node_modules/tape/lib/test.js:476:7)
          at Test.bound [as equal] (/home/runner/work/node-exist/node-exist/node_modules/tape/lib/test.js:95:17)
          at Test.<anonymous> (/home/runner/work/node-exist/node-exist/spec/tests/documents.js:102:10)
          at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
  ...