URI template support in RLC

[MaryGao]

fixes https://github.com/Azure/autorest.typescript/issues/2793 fixes https://github.com/Azure/autorest.typescript/issues/2792

Breakings

CollectionFormat with csv and multi are most commonly used cases, for csv there is no breaking. And for multi there will be a breaking and enabling the option compatibilityMode: true would mitigate this breaking.

CollectionFormat with tsv is no longer supported and we are not aware of any real cases yet.

Possible values

• allowReserved: true/false
• value: primitive/array/object
• explode: true/false
• style: form/spaceDelimited/pipeDelimited

In-scoped cases

Path allowReserved

Support to define allowReserved for path parameter but the style and explode support for path parameter is not in-scope of this pr. The default for allowReserved would be

• allowReserved = false

allowReserved	Supported
true	y
false	y

Query expansion

Please note the allowReserved for query paremeter is not in scope of this pr. Except the form style we would also include the spaceDelimited and pipeDelimited mainly considering backward-compatibility. The default setting would be:

• style = form & explode = false

Style	Explode	Uri Template	Primitive value id = 5	Array id = [3, 4, 5]	Object id = {"role": "admin", "firstName": "Alex"}	Supported
form	false	/users{?id}	/users?id=5	/users?id=3,4,5	/users?id=role,admin,firstName,Alex	y
form*	true*	/users{?id*}	/users?id=5	/users?id=3&id=4&id=5	/users?role=admin&firstName=Alex	y
spaceDelimited	false	n/a	n/a	/users?id=3%204%205	n/a	y
pipeDelimited	false	n/a	n/a	/users?id=3|4|5	n/a	y

Out-of-scope cases

• tsv tab separated format(no real case yet.)
• Header expansion(header design is not changed and any support in header is out-of this pr's scope.)
• Path with explode
• Query with allowReserved