gzip and metadata

[lastmjs]

Soon dfx will automatically gzip Wasm for us, allowing us to simply pass the regular .wasm file into dfx.json. Also, the metadata section of dfx.json will work for Azle at that point. Once this happens, we should use the metadata section in dfx.json to set candid:service and cdk:name.

Using the metadata section of dfx.json will be much more elegant than forcing ic-wasm as a dependency or using link sections in the code, candid:service I believe is done automatically if you just specify it, and cdk name should be easy...cdk version would be harder, but it's debatable whether or not that should be in there anyway.

Here's what I believe the metadata section should look like:

            "metadata": [
                {
                    "name": "candid:service"
                },
                {
                    "name": "cdk",
                    "contents": "azle"
                }
            ],