Fix TS composite btree range scans

[JasonAtClockwork]

Description of Changes

Closes #5454

Fixes TypeScript modules for indexes filter() and delete() methods where the final provided argument is a Range.

• Added a helper used by filter() and delete() to choose between point scans and ranged scans
• Fixed serializeRange so range bounds are sliced after the prefix instead of the start

API and ABI breaking changes

No breaking changes this is a bug fix

Expected complexity level and risk

2 - Limited change to the index logic for filter() and delete()

Testing

• Added small unit tests for filter() and delete() with a composite key ending in Range
• Ran a full e2e throwaway project with dozens of different filters and deletes using composite keys/ranges and point