[crystal-lang] Various fixes for Crystal client (#22465)

* [crystal] implement "multi" params

See: https://github.com/mamantoha/crest?tab=readme-ov-file#crestnestedparamsencoder

* [crystal] remove useless templates (imported from ruby)

Author: n-rodriguez

modules/openapi-generator/src/main/resources/crystal/Gemfile.mustache

@@ -131,7 +131,7 @@ module {{moduleName}}
       cookie_params = Hash(String, String).new
 
       # query parameters
-      query_params = Hash(String, String).new
+      query_params = Hash(String, String | Array(String)).new
       {{#queryParams}}
       query_params["{{{baseName}}}"] = {{#collectionFormat}}@api_client.build_collection_param({{{paramName}}}, :{{{collectionFormat}}}) unless {{{paramName}}}.nil?{{/collectionFormat}}{{^collectionFormat}}{{{paramName}}}.to_s unless {{{paramName}}}.nil?{{/collectionFormat}}
       {{/queryParams}}

modules/openapi-generator/src/main/resources/crystal/Rakefile.mustache

@@ -109,8 +109,7 @@ module {{moduleName}}
       when :pipes
         param.join("|")
       when :multi
-        # TODO: Need to fix this
-        raise "multi is not supported yet"
+        param
       else
         raise "unknown collection format: #{collection_format.inspect}"
       end
@@ -147,7 +146,8 @@ module {{moduleName}}
         cookies: cookie_params,
         form: form_or_body,
         logging: @config.debugging,
-        handle_errors: false
+        handle_errors: false,
+        params_encoder: Crest::NestedParamsEncoder
       )
 
       response = request.execute

modules/openapi-generator/src/main/resources/crystal/api.mustache

@@ -67,7 +67,7 @@ module Petstore
       cookie_params = Hash(String, String).new
 
       # query parameters
-      query_params = Hash(String, String).new
+      query_params = Hash(String, String | Array(String)).new
       query_params["type"] = _type.to_s unless _type.nil?
       query_params["http_debug_option"] = http_debug_option.to_s unless http_debug_option.nil?
 

modules/openapi-generator/src/main/resources/crystal/api_client.mustache

@@ -45,7 +45,7 @@ module Petstore
       cookie_params = Hash(String, String).new
 
       # query parameters
-      query_params = Hash(String, String).new
+      query_params = Hash(String, String | Array(String)).new
 
       # header parameters
       header_params = Hash(String, String).new
@@ -110,7 +110,7 @@ module Petstore
       cookie_params = Hash(String, String).new
 
       # query parameters
-      query_params = Hash(String, String).new
+      query_params = Hash(String, String | Array(String)).new
 
       # header parameters
       header_params = Hash(String, String).new
@@ -172,7 +172,7 @@ module Petstore
       cookie_params = Hash(String, String).new
 
       # query parameters
-      query_params = Hash(String, String).new
+      query_params = Hash(String, String | Array(String)).new
       query_params["status"] = @api_client.build_collection_param(status, :csv) unless status.nil?
 
       # header parameters
@@ -236,7 +236,7 @@ module Petstore
       cookie_params = Hash(String, String).new
 
       # query parameters
-      query_params = Hash(String, String).new
+      query_params = Hash(String, String | Array(String)).new
       query_params["tags"] = @api_client.build_collection_param(tags, :csv) unless tags.nil?
 
       # header parameters
@@ -300,7 +300,7 @@ module Petstore
       cookie_params = Hash(String, String).new
 
       # query parameters
-      query_params = Hash(String, String).new
+      query_params = Hash(String, String | Array(String)).new
 
       # header parameters
       header_params = Hash(String, String).new
@@ -363,7 +363,7 @@ module Petstore
       cookie_params = Hash(String, String).new
 
       # query parameters
-      query_params = Hash(String, String).new
+      query_params = Hash(String, String | Array(String)).new
 
       # header parameters
       header_params = Hash(String, String).new
@@ -428,7 +428,7 @@ module Petstore
       cookie_params = Hash(String, String).new
 
       # query parameters
-      query_params = Hash(String, String).new
+      query_params = Hash(String, String | Array(String)).new
 
       # header parameters
       header_params = Hash(String, String).new
@@ -493,7 +493,7 @@ module Petstore
       cookie_params = Hash(String, String).new
 
       # query parameters
-      query_params = Hash(String, String).new
+      query_params = Hash(String, String | Array(String)).new
 
       # header parameters
       header_params = Hash(String, String).new