Switch to or logic when multiple merge ids in restriction

[samuelbray32]

Description

• Merge.extract_merge_id() was introduced in Apply restrictions on parent tables in fetch_nwb #1086 to help allow restriction by Merge table or parent table in Merge.fetch_nwb()
• The logic of this function created a And restriction when multiple merge ids were present in the restriction
  • This would always lead to an empty table when applied since an entry can't match 2 different merge_id values
• This PR changes the restriction returned by Merge.extract_merge_id() to or logic to allow proper function.

Checklist:

• N This PR should be accompanied by a release: (yes/no/unsure)
• NA If release, I have updated the CITATION.cff
• N This PR makes edits to table definitions: (yes/no)
• NA If table edits, I have included an alter snippet for release notes.
• NA If this PR makes changes to position, I ran the relevant tests locally.
• I have updated the CHANGELOG.md with PR number and description.
• NA I have added/edited docs/notebooks to reflect the changes

[CBroz1]

This will need tests in the future, but I can work add them in my next pass if you don't have bandwidth right now