fix: resolve validation and parsing bugs in core utilities

[Prabhdeep1701]

What?

Fixed 7 bugs across payload core utilities:

• addDataAndFileToRequest.ts — JSON.parse on _payload field had no try/catch, throwing unhandled SyntaxError on invalid JSON
• validations.ts — point field validator had swapped lng/lat NaN checks (value[1] checked against lng, value[0] against lat)
• validations.ts — removed dead typeof lng !== 'number' branch in point validator (always false since parseFloat returns number)
• validations.ts — upload/relationship error messages appended a numeric index to each invalid value due to swapped .map() parameter names
• afterRead/promise.ts — getBlockSelect() called with block! before the if (block) guard, risking runtime error on undefined block
• parseParams/index.ts — key in params throws TypeError when params is null/undefined (documented as "current implementation bug" in tests)
• mergeListSearchAndWhere.ts — else if and else branches in hoistQueryParamsToAnd executed identical code

Why?

These are runtime correctness bugs. The swapped lng/lat check causes valid point inputs to be rejected. The unguarded JSON.parse crashes the server on malformed multipart payloads. The non-null assertion can throw on documents with unknown block types.

How?

• Wrapped _payload JSON.parse in try/catch matching the pattern used for fields.file on the next line
• Swapped value[0]/value[1] indices to match their correct coordinate variables
• Moved getBlockSelect() inside the existing if (block) guard
• Added early return in parseParams for null/undefined, updated tests from "throws TypeError" to "returns {}"
• Simplified .map() callback to remove misleading index
• Collapsed duplicate else branches

[Prabhdeep1701]

Hey, this PR fixes 7 bugs found through code review — validation edge cases, an unguarded JSON.parse, and a few code quality issues. Let me know if any changes are needed!