Fixes #20516
Follow up to #21747 and #21746
This tackles the last point of #20516 where certain inputs weren't
accepted in the other zlib methods
This adds the `toU8` conversion of `_brotli` to `_zlib.mjs`, when we
create the ZLibBuffer, we'll sanitize the input. I noticed that the
async had no handler for `string` input so I added that as well.
This fixes point 3 of https://github.com/denoland/deno/issues/20516
This PR creates consistency between the sync and async versions of the
brotli compress where we will always return a buffer like Node.
This fixes point 2 of #20516
This adds a conversion from Dataview/Buffer by returning `obj.buffer`
which can be converted to a `UInt8Array`.
Question: Regarding point 4 of the mentioned issue would it be
appropriate to copy the toU8 helper to the `zlib.mjs` methods?
Fixes https://github.com/denoland/deno/issues/19816
In that issue, I suggest switching over the other brotli functionality
to the Rust API provided by the `brotli` crate. Here, I only do that
with the `brotli_decompress` function to fix the bug with buffers longer
than 4096 bytes.
