[ruby] Support for per-operation servers (#7415)

* Support server configuration per operation

* regenerated+tests

* base_url fix

* support not templated urls

* revert update of ruby docs

samples/openapi3/client/features/dynamic-servers/ruby/docs/UsageApi.md

@@ -0,0 +1,96 @@
+# DynamicServers::UsageApi
+
+All URIs are relative to *http://petstore.swagger.io:80/v2*
+
+Method | HTTP request | Description
+------------- | ------------- | -------------
+[**custom_server**](UsageApi.md#custom_server) | **GET** /custom | Use custom server
+[**default_server**](UsageApi.md#default_server) | **GET** /default | Use default server
+
+
+
+## custom_server
+
+> Object custom_server
+
+Use custom server
+
+Use custom server
+
+### Example
+
+```ruby
+# load the gem
+require 'dynamic_servers'
+
+api_instance = DynamicServers::UsageApi.new
+
+begin
+  #Use custom server
+  result = api_instance.custom_server
+  p result
+rescue DynamicServers::ApiError => e
+  puts "Exception when calling UsageApi->custom_server: #{e}"
+end
+```
+
+### Parameters
+
+This endpoint does not need any parameter.
+
+### Return type
+
+**Object**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: application/json
+
+
+## default_server
+
+> Object default_server
+
+Use default server
+
+Use default server
+
+### Example
+
+```ruby
+# load the gem
+require 'dynamic_servers'
+
+api_instance = DynamicServers::UsageApi.new
+
+begin
+  #Use default server
+  result = api_instance.default_server
+  p result
+rescue DynamicServers::ApiError => e
+  puts "Exception when calling UsageApi->default_server: #{e}"
+end
+```
+
+### Parameters
+
+This endpoint does not need any parameter.
+
+### Return type
+
+**Object**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: application/json
+