Add decorator to make a parameter to client level

[tadelesh]

In swagger, we have x-ms-parameter-location extension to set a parameter to client level. We should also support it in TCGC as a client customization. The main usage scenario is for ARM.

[qiaozha]

Is there a case that we need a not-subscriptionId parameter to be client level? I wonder if we should limit the scope of this customization to subscripitonId parameter, and ARM only?

I have handled so many cases where service team abused of x-ms-parameter-location and causes problems for us because we honor this value, and java completely ignore x-ms-parameter-location if it's a not-subscriptionId parameter.

[tadelesh]

@qiaozha ref: #914, we got customer ask for data plane for such feature.

[qiaozha]

Interesting, can we at least set the default value into method level ?

[tadelesh]

Interesting, can we at least set the default value into method level ?

sure.

[lmazuel]

See #914