### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

When creating base-path-mappings on an API Gateway, there is a special `(none)` path when you don't specify a path during creation. Localstack stores this as `basePath: "(none)"` internally.
When you query to get the base paths, the URLs are escaped by the client (verified in both awscli and terraform) so the basePath is sent as `%28none%29` in the url.
Localstack doesn't appear to be decoding urls and when you attempt to get-base-path-mapping it fails in a string comparison of `(none)` to `%28none%29`.

```shell
> aws --endpoint-url=http://localhost:4566 apigateway get-base-path-mapping --domain-name example.com --base-path "(none)"

An error occurred (NotFoundException) when calling the GetBasePathMapping operation: Base path mapping not found: %28none%29
```

### Expected Behavior

When you attempt to get-base-path-mappings after creating one with the (none) path, it succeeds and returns the mapping.

```
> aws --endpoint-url=http://localhost:4566 apigateway get-base-path-mapping --domain-name example.com --base-path "(none)"

{
    "basePath": "(none)",
    "restApiId": "uyy4c3dsho",
    "stage": "dev"
}
```


### How are you starting LocalStack?

With the `localstack` script

### Steps To Reproduce

#### How are you starting localstack (e.g., `bin/localstack` command, arguments, or `docker-compose.yml`)

    make start

#### Client commands (e.g., AWS SDK code snippet, or sequence of "awslocal" commands)

    awslocal apigateway create-rest-api --name "testgw"
    awslocal apigateway create-base-path-mapping --domain-name example.com --rest-api-id <from output above> --stage dev
    awslocal apigateway get-base-path-mapping --domain-name example.com --base-path "(none)"



### Environment

```markdown
- OS: fedora 34
- LocalStack: latest
```


### Anything else?

https://docs.aws.amazon.com/apigateway/api-reference/link-relation/basepathmapping-by-base-path/
region_details = APIGatewayRegion.get()
    domain_name = get_domain_from_path(path)
    base_path = get_base_path_from_path(path)
    mappings_list = region_details.base_path_mappings.get(domain_name) or []
    mapping = ([m for m in mappings_list if m["basePath"] == base_path] or [None])[0]
    if mapping is None:
        return make_error_response(
            "Not found: mapping for domain name %s, base path %s in list %s"
            % (domain_name, base_path, mappings_list),
            code=404,
        )
    operations = data["patchOperations"]
    operations = operations if isinstance(operations, list) else [operations]
    for operation in operations:
        if operation["path"] == "/restapiId":
            operation["path"] = "/restApiId"
    result = apply_json_patch_safe(mapping, operations)
    for i in range(len(mappings_list)):
        if mappings_list[i]["basePath"] == base_path:
            mappings_list[i] = result
    return make_json_response(to_base_mapping_response_json(domain_name, base_path, result))
def delete_base_path_mapping(path):