feat: 根据导入和导出的headers，需要保证原来定义的顺序和配置项不被前端覆盖掉

lib/tallty_import_export/export.rb

 module TalltyImportExport
   class Export
-    attr_reader :klass
+    attr_reader :klass, :context
 
     def initialize klass
       @klass = klass
+      @context = Context.new({})
     end
 
     # [
@@ -150,6 +151,8 @@ module TalltyImportExport
       @group_where = "#{@group_by}_eq" if @group_by.present?
       @headers ||= options.delete(:headers)
       @each_method ||= options.delete(:each_method)
+      @params = options
+      context.params = @params
     end
 
     def with_scope records
@@ -157,7 +160,17 @@ module TalltyImportExport
     end
 
     def export_headers_result
-      @headers ||= export_headers
+      if @headers.present?
+        headers_hash = @headers.to_h { |header| [header.with_indifferent_access[:key], header] }.with_indifferent_access
+        export_headers.select do |_header|
+          _header.with_indifferent_access[:key].to_s.in?(headers_hash.keys)
+        end.map do |_header|
+          _header.with_indifferent_access!
+          _header.merge(headers_hash[_header[:key]].delete_if { |k, v| v.blank? })
+        end
+      else
+        @headers = export_headers
+      end
     end
 
     def export_headers **args
@@ -176,7 +189,7 @@ module TalltyImportExport
         elsif header[:json]
           record.send(header[:json])[header[:key]]
         elsif header[:proc] && header[:proc].respond_to?(:call)
-          header[:proc].call(record)
+          header[:proc].call(record, context)
         else
           try_method(record, header[:key])
         end

lib/tallty_import_export/import.rb

@@ -136,13 +136,12 @@ module TalltyImportExport
     # 需要合并proc，前端没有办法把proc传过来
     def import_headers_result
       if @headers.present?
-        import_header_hash = import_headers.to_h { |header| [header.with_indifferent_access[:key], header] }.with_indifferent_access
-        @headers.map do |header|
-          key = header[:key]
-          if import_header_hash.dig(key, :proc).present?
-            header[:proc] = import_header_hash.dig(key, :proc)
-          end
-          header
+        headers_hash = @headers.to_h { |header| [header.with_indifferent_access[:key], header] }.with_indifferent_access
+        import_headers.select do |_header|
+          _header.with_indifferent_access[:key].to_s.in?(headers_hash.keys)
+        end.map do |_header|
+          _header.with_indifferent_access!
+          _header.merge(headers_hash[_header[:key]].delete_if { |k, v| v.blank? })
         end
       else
         @headers = import_headers