[Bug] CI build script accepts flags as values for required options

### Search before asking

- [x] I searched in the [issues](https://github.com/apache/paimon-cpp/issues) and found nothing similar.

### Paimon-cpp version

### Paimon version

Current `main` branch.

### Minimal reproduce step

Run one of the following commands:

```bash
ci/scripts/build_paimon.sh --source_dir --enable_asan

ci/scripts/build_paimon.sh \
--source_dir . \
--build_type --enable_asan

ci/scripts/build_paimon.sh \
--source_dir . \
--lint_git_target_commit --enable_asan
```

The script treats the following option as the value of the preceding option and continues until a later command fails or CMake is invoked with an invalid value.

The script also accepts unsupported build types:

```
ci/scripts/build_paimon.sh \
--source_dir . \
--build_type Profile
```

### What doesn't meet your expectations?

Options that require a value should reject an empty value or another `--option` with a clear error message.

The `--build_type` option should only accept the standard CMake build types used by the project:
- `Debug`
- `Release`
- `RelWithDebInfo`
- `MinSizeRel`
Invalid arguments should be rejected before creating build directories or invoking CMake.

The argument validation behavior is currently not covered by dedicated script-level tests.

### Anything else?

_No response_

### Are you willing to submit a PR?

- [x] I'm willing to submit a PR!

Start with ci/scripts/build_paimon.sh and reproduce the listed commands to trace how required option values and --build_type are validated. Add script-level coverage for missing or option-like values and unsupported build types; done means invalid arguments fail before build directories or CMake are invoked, while the four listed CMake build types remain accepted.

Written by the indexing model from the issue text.