speed improvement for getAnnotationsOnPage

[peterstadler]

Description, Context and related Issue

This PR improves the performance of the getAnnotationsOnPage endpoint

How Has This Been Tested?

Testing was done with a recent development version of getAnnotationsOnPage.xql vs the improved version presented here. As test data served the clarinet quintet and the improvement was monitored with Monex. I simply issued the following request five times: http://localhost:8080/exist/apps/Edirom-Online/data/xql/getAnnotationsOnPage.xql?_dc=1726123824958&uri=xmldb%3Aexist%3A%2F%2F%2Fdb%2Fapps%2Fweber-klarinettenquintett-eol-emeritus%2Fsources%2Fsource-1.xml&pageId=facsimile-20010010&lang=de&edition=xmldb%3Aexist%3A%2F%2F%2Fdb%2Fapps%2Fweber-klarinettenquintett-eol-emeritus%2Fedition.xml

before

after

Types of changes

• performance improvement

Checklist

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have performed a self-review of my code
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[bwbohl]

great work!