### 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/
"result",
        "url",
        "path_with_replace",
    ],
)
class TestAPIGateway(unittest.TestCase):
    
    APIGATEWAY_DATA_INBOUND_TEMPLATE = """{
        "StreamName": "%s",
        "Records": [
            #set( $numRecords = $input.path('$.records').size() )
            #if($numRecords > 0)
            #set( $maxIndex = $numRecords - 1 )
            #foreach( $idx in [0..$maxIndex] )
            #set( $elem = $input.path("$.records[${idx}]") )
            #set( $elemJsonB64 = $util.base64Encode($elem.data) )
            {
                "Data": "$elemJsonB64",
                "PartitionKey": #if( $elem.partitionKey != '')"$elem.partitionKey"
                                #else"$elemJsonB64.length()"#end
            }#if($foreach.hasNext),#end
            #end
            #end
        ]
    }"""
    
    API_PATH_DATA_INBOUND = "/data"
    API_PATH_HTTP_BACKEND = "/hello_world"
    API_PATH_LAMBDA_PROXY_BACKEND = "/lambda/foo1"
    API_PATH_LAMBDA_PROXY_BACKEND_WITH_PATH_PARAM = "/lambda/{test_param1}"