feat(backend/kernel): wire TSparkParameter through to kernel bind_param

[vikrantpuppala]

Stacks on #787 (kernel backend). Pairs with kernel PR databricks/databricks-sql-kernel#18.

Summary

Lifts the `NotSupportedError` the kernel backend currently raises for parametrized queries. The kernel-side PyO3 binding for `Statement.bind_param` lands in databricks-sql-kernel#18; this PR wires the connector's `TSparkParameter` shape through to it.

Before this PR, calling `cursor.execute("SELECT ?", [IntegerParameter(42)])` on `use_sea=True` raised:

```
NotSupportedError: Parameter binding is not yet supported on the kernel backend
```

After: positional parameter binding works end-to-end.

What it does

`bind_tspark_params(kernel_stmt, parameters)` in `type_mapping.py` forwards each `TSparkParameter` to the kernel as `(ordinal, value.stringValue, type)`:

• `ordinal` is the 1-based position in the parameters list (matches kernel's SEA-wire convention).
• `value.stringValue` is the connector's already-string-encoded value (or `None` for SQL NULL).
• `type` is the SQL type name the connector produces (`"INT"`, `"DECIMAL(10,2)"`, etc.).

The connector's `ordinal: bool` flag is checked only to reject named bindings — kernel v0 doesn't accept named bindings on the SEA wire, so we surface that at the connector layer with a pointed `NotSupportedError` rather than letting the server reject.

What's supported

Every type the connector's native parameter classes emit:

• `BOOLEAN`, `TINYINT` / `SMALLINT` / `INT` / `BIGINT`, `FLOAT` / `DOUBLE`
• `STRING`, `DATE`, `TIMESTAMP` / `TIMESTAMP_NTZ`, `INTERVAL`
• `DECIMAL(p,s)` (precision/scale carried in the SQL type string; kernel parses them)
• `VOID` / Python `None`

What's not supported (known gaps, raises `NotSupportedError`)

• Named bindings (`cursor.execute(":foo = ?", [param_named("foo", ...)])`) — kernel v0 SEA wire is positional-only.
• Compound types (`ARRAY` / `MAP` / `STRUCT`) — kernel parser rejects; surfaces as `KernelError(InvalidArgument)`.
• `BINARY` — SEA wire limitation kernel-side; documented workaround is hex-encode + `unhex(?)` in SQL.

Test plan

• 6 new unit tests in `tests/unit/test_kernel_type_mapping.py` — positional forwarding, None / VOID, named binding rejection, missing-type defaulting, empty list. 45/45 pass.

• Pre-existing unit suite still green: 625 pass.

• 3 new live e2e tests in `tests/e2e/test_kernel_backend.py` against dogfood:

  • Mixed-type round-trip (`IntegerParameter`, `StringParameter`, `BooleanParameter`)
  • `None` parameter
  • `DECIMAL` parameter (precision/scale flows through the SQL type string)

  14/14 pass.

• `cargo test` / `cargo clippy` / `cargo fmt --check` clean on the kernel side (PR Make GetOperationStatus attempts retryable #18).

This pull request and its description were written by Isaac.