(apigatewayv2): support multi level base path mappings

Hi,

When I tried to configure a API mapping with a / it throws me an error complaining a / in the path is not a valid. However, according to the documentation a / is also allowed.

Reproduction Steps

        apigatewayv2.ApiMapping(self, "AccountsGetBasePathMapping",
            api=accounts_get_api,
            domain_name=apigateway.DomainName.from_domain_name_attributes(self, "ApiMyDomainComApiGwCustomDomain",
                domain_name="api.mydomain.com",
                domain_name_alias_hosted_zone_id="xxxx",
                domain_name_alias_target="xxxx.execute-api.eu-west-1.amazonaws.com."
            ),
            api_mapping_key="accounts/get",
            stage=accounts_get_api_stage,        
        )

What did you expect to happen?

To be able to configure a api mapping with a /

What actually happened?

Error: An ApiMapping key may contain only letters, numbers and one of $-_.+!*'(),

Environment

• CDK CLI Version : 1.97.0 (build c52c2dc)
• Framework Version: 1.96.0
• Node.js Version: v15.13.0
• OS : OSX 11.2.3
• Language (Version): Python 3.8

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This is 🐛 Bug Report

[nija-at]

Time?

Yes.

We also accept pull requests.

[nija-at]

Hi @tvb, I’ve re-classified this issue as a feature request.

Until we can implement this, you may use our escape hatch mechanism to bypass this validation.