[Extensions][Go][Java] Test x-auth-id-alias

Created by: jirikuncar

Adds tests for go-experimental to test x-auth-id-alias extension.

Based on discussion in #6469.

• Go test file: https://github.com/OpenAPITools/openapi-generator/pull/6642/files#diff-8e0352a3f9f1548beef9453992b7719d

PR checklist

• Read the contribution guidelines.
• If contributing template-only or documentation-only changes which will change sample output, build the project beforehand.
• Run the shell script ./bin/generate-samples.shto update all Petstore samples related to your fix. This is important, as CI jobs will verify all generator outputs of your HEAD commit as it would merge with master. These must match the expectations made by your contribution. You may regenerate an individual generator by passing the relevant config(s) as an argument to the script, for example ./bin/generate-samples.sh bin/config/java*. For Windows users, please run the script in Git BASH.
• File the PR against the correct branch: master
• Copy the technical committee to review the pull request if your PR is targeting a particular programming language.

cc @antihax (2017/11) @bvwells (2017/12) @grokify (2018/07) @kemokemo (2018/09) @bkabrda (2019/07)

bin/configs/go-experimental-extensions-x-auth-id-alias.yaml

+generatorName: go-experimental
+outputDir: samples/openapi3/client/extensions/x-auth-id-alias/go-experimental
+inputSpec: modules/openapi-generator/src/test/resources/3_0/extensions/x-auth-id-alias.yaml
+templateDir: modules/openapi-generator/src/main/resources/go-experimental
+additionalProperties:
+  packageName: x_auth_id_alias

bin/configs/java-jersey2-extensions-x-auth-id-alias.yaml

+generatorName: java
+outputDir: samples/openapi3/client/extensions/x-auth-id-alias/java/jersey2-java8
+library: jersey2
+inputSpec: modules/openapi-generator/src/test/resources/3_0/extensions/x-auth-id-alias.yaml
+additionalProperties:
+  artifactId: openapi3-extensions-x-auth-id-alias-jersey2-java8
+  hideGenerationTimestamp: true

modules/openapi-generator/src/main/resources/go-experimental/api.mustache

@@ -252,13 +252,24 @@ func (r api{{operationId}}Request) Execute() ({{#returnType}}{{{.}}}, {{/returnT
 	if r.ctx != nil {
 		// API Key Authentication
 		if auth, ok := r.ctx.Value(ContextAPIKeys).(map[string]APIKey); ok {
-			if auth, ok := auth["{{#vendorExtensions.x-auth-id-alias}}{{.}}{{/vendorExtensions.x-auth-id-alias}}{{^vendorExtensions.x-auth-id-alias}}{{name}}{{/vendorExtensions.x-auth-id-alias}}"]; ok {
+			{{#vendorExtensions.x-auth-id-alias}}
+			if apiKey, ok := auth["{{.}}"]; ok {
 				var key string
-				if auth.Prefix != "" {
-					key = auth.Prefix + " " + auth.Key
+				if prefix, ok := auth["{{name}}"]; ok && prefix.Prefix != "" {
+					key = prefix.Prefix + " " + apiKey.Key
 				} else {
-					key = auth.Key
+					key = apiKey.Key
 				}
+			{{/vendorExtensions.x-auth-id-alias}}
+			{{^vendorExtensions.x-auth-id-alias}}
+			if apiKey, ok := auth["{{name}}"]; ok {
+				var key string
+				if apiKey.Prefix != "" {
+					key = apiKey.Prefix + " " + apiKey.Key
+				} else {
+					key = apiKey.Key
+				}
+			{{/vendorExtensions.x-auth-id-alias}}
 				{{#isKeyInHeader}}
 				localVarHeaderParams["{{keyParamName}}"] = key
 				{{/isKeyInHeader}}

samples/client/petstore/go-experimental/go-petstore/api_fake_classname_tags123.go

@@ -97,12 +97,12 @@ func (r apiTestClassnameRequest) Execute() (Client, *_nethttp.Response, error) {
 	if r.ctx != nil {
 		// API Key Authentication
 		if auth, ok := r.ctx.Value(ContextAPIKeys).(map[string]APIKey); ok {
-			if auth, ok := auth["api_key_query"]; ok {
+			if apiKey, ok := auth["api_key_query"]; ok {
 				var key string
-				if auth.Prefix != "" {
-					key = auth.Prefix + " " + auth.Key
+				if apiKey.Prefix != "" {
+					key = apiKey.Prefix + " " + apiKey.Key
 				} else {
-					key = auth.Key
+					key = apiKey.Key
 				}
 				localVarQueryParams.Add("api_key_query", key)
 			}