Stream CSV when processing server entities

[seadowg]

Closes #6350
Blocked by getodk/javarosa#792

This removes the CSV to XML parsing that was being performed and instead just parses the instance CSV directly as a stream which should improve the memory footprint when downloading entity forms. There may be a slight speed up as well as we don't convert the CSV to an in-mem XML representation, but this will be minor at best.

Why is this the best possible solution? Were any other approaches considered?

Not a lot to discuss here!

How does this change affect users? Describe intentional changes to behavior and behavior that could have accidentally been affected by code changes. In other words, what are the regression risks?

The main risk will be to forms with entities (follow up and update forms). Nothing else should be affected. The only device that predictably experienced OOMs was @lognaturel's Galaxy A13, so let's let her confirm that this fixes that.

Before submitting this PR, please make sure you have:

• added or modified tests for any new or changed behavior
• run ./gradlew connectedAndroidTest (or ./gradlew testLab) and confirmed all checks still pass
• added a comment above any new strings describing it for translators
• added any new strings with date formatting to DateFormatsTest
• verified that any code or assets from external sources are properly credited in comments and/or in the about file.
• verified that any new UI elements use theme colors. UI Components Style guidelines

[lognaturel]

I can confirm that this allows me to download and use the 100k Entities Filter form with the Galaxy A13. 👍

[WKobus]

Tested with Success

Verified on device with Android 14

Verified cases:

• Update and registration forms
• Performance on 100k entity forms

[dbemke]

Tested with Success

Verified on device with Android 10