* Add an initial set of performance benchmarks

* make it work with pre-existing dbs too

* Add whether cython is enabled

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Co-authored-by: Martin Gallwey <mgy5@3ds.com>

* Optimize result fetching via block-draining and check inlining

Accelerate data retrieval pathways in the Cursor class by optimizing row
iteration and reducing interpreter overhead on high-frequency method loops.

Detailed changes:
- fetchone: Inline the `_check_closed()` state verification directly into the
  method body. This removes function-call stack overhead for every individual
  row retrieved.
- fetchall: Refactor the loop to slice and drain the current in-memory result
  batch in bulk using `list.extend()` instead of sequentially invoking
  `fetchone()` row by row.
- fetchall: Directly request the next network payload batch via
  `fetch_result_set_next` once the in-memory collection is exhausted, updating
  total `rownumber` tracking as a single block operation.
- fetchall: Add a defensive guard clause against unallocated result sets to
  ensure strict DB-API compatibility.

* merge fetchmany and fetchall

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Co-authored-by: Martin Gallwey <mgy5@3ds.com>

* Optimize network I/O buffering and parameter type dispatch

Streamline the data-ingestion pipeline and outbound parameter encoding loop by
eliminating high-overhead memory copies, optimizing primitive type comparisons,
and increasing TCP window throughput.

Detailed changes:
- session: Request an opportunistic 1 MiB socket receive buffer (SO_RCVBUF) to
  minimize fragmented kernel reads across heavy wire payload streams.
- session: Rewrite `__readFully` to pre-allocate a single message-sized
  bytearray. Populate it directly using zero-copy `sock.recv_into()` on a
  slicing memoryview, replacing an iterative chunk concatenation loop.
- encodedsession: Update `recv()` and input stream targets to return and use
  raw mutable bytearray buffers directly, cutting down an extra copy.
- encodedsession: Refactor `putValue` to use rapid pointer-level exact type
  comparisons (`type(v) is X`) for common database primitives (int, str, float,
  bool) before falling back to heavier hierarchy-aware `isinstance()` checks
  for the long tail.

* Remove silly comment

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Co-authored-by: Martin Gallwey <mgy5@3ds.com>