fix(ChunkedOutputFilter): reset position chunks buffer when recycled

[choijunwoo]

Problem

ChunkedOutputFilter reuses the lastChunk, crlfChunk, and endChunk
ByteBuffer instances across responses.

The end() method resets these buffers only after the corresponding downstream
write completes successfully. If HttpOutputBuffer.doWrite() consumes part of a
buffer and then throws an IOException, the reset is skipped.

When the owning Http11Processor is subsequently recycled, the same
ChunkedOutputFilter may be reused with the stale buffer position. For example,
if the first two bytes (0\r) of the terminal chunk (0\r\n\r\n) were consumed
before the exception, the next response would write only the remaining
\n\r\n.

Fix

Reset the position to zero and the limit to the capacity for all reusable chunk
buffers in ChunkedOutputFilter.recycle():

• lastChunk
• crlfChunk
• endChunk

This mirrors the reset already performed after successful writes while also
covering exceptional write paths.