Support AllowReserved in Path Implementation

[lmazuel]

[pshao25]

For this case:

model PathModel {
  @path(#{ allowReserved: true }) path1: string;
  @path(#{ allowReserved: true }) path2: string;
}

interface WidgetService {
  @route("/here") op c1(...PathModel): void;
}

Current:

internal HttpMessage CreateTestRequest(string path1, string path2, RequestContext context)
{
    ...
    uri.Reset(_endpoint);
    uri.AppendPath("/here/", false);
    uri.AppendPath(path1, true); <= encode true
    uri.AppendPath("/", false);
    uri.AppendPath(path2, true);
    ...
}

Change to

internal HttpMessage CreateTestRequest(string path1, string path2, RequestContext context)
{
    ...
    uri.Reset(_endpoint);
    uri.AppendPath("/here/", false);
    uri.AppendPath(path1, false); <= encode false
    uri.AppendPath("/", false);
    uri.AppendPath(path2, false);
    ...
}