Fixes #29267

## Problem

`Uint8Array` values nested inside objects or arrays are serialized as
numeric-keyed objects (e.g. `{"0":72,"1":101,"2":108,"3":108,"4":111}`)
instead of base64 strings when stored in a `Json` field. Top-level
`Uint8Array` values are unaffected.

This was introduced in #29182, which added `deserializeJsonObject()`
before `JSON.stringify()` in the parameterization step to fix Date
handling in Json fields. `deserializeJsonObject` correctly converts `{
$type: 'Bytes', value: 'SGVsbG8=' }` back to a `Uint8Array`, but
`JSON.stringify` cannot natively serialize `Uint8Array` and falls back
to `{"0":72,...}`.

## Fix

Replace `JSON.stringify` with `safeJsonStringify` (already exported from
`@prisma/client-engine-runtime`) in both the `#handleArray` and
`#handleObject` methods of `Parameterizer`. `safeJsonStringify` uses a
custom replacer that converts `ArrayBuffer.isView` values to base64
strings and `BigInt` to string representation.

## Tests

Added a functional regression test in
`packages/client/tests/functional/issues/29267-uint8array-in-json/`
covering:
- `Uint8Array` nested inside an object
- `Uint8Array` nested inside an array
- `Uint8Array` passed directly (already working, included for
completeness)
- Deeply nested `Uint8Array`

<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit

## Release Notes

* **Bug Fixes**
* Improved JSON serialization for parameter handling to properly convert
Uint8Array values to base64 strings when stored in JSON fields, ensuring
correct data handling across create operations.

* **Tests**
* Added comprehensive test coverage for Uint8Array serialization in JSON
fields, including scenarios with nested objects, arrays, and various
nesting depths across multiple database providers.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->