Previously, the receiver could retain one `Buffer` entry per buffered
chunk or message fragment until enough data was parsed or the message
completed. A peer could use many tiny fragments/chunks and make retained
memory scale with retained part count rather than message payload size.

Add configurable `maxBufferedChunks` and `maxFragments` options to bound
the number of retained parts. When either limit is exceeded, emit
a `WS_ERR_TOO_MANY_BUFFERED_PARTS` error and close the connection with
close code 1008.

Signed-off-by: Nadav0077 <18245584+Nadav0077@users.noreply.github.com>

Ensure that empty fragments are counted against the `maxFragments`
limit.

Use smaller and safer default values for the `maxBufferedChunks` and
`maxFragments` options.

Closes #2331
Closes #2332

Fixes #2333