feature[Excel]: support bookType option (#1144)

Documentation: https://panjiachen.github.io/vue-element-admin-site/feature/component/excel.html

src/views/excel/components/FilenameOption.vue

@@ -0,0 +1,28 @@
+<template>
+  <div style="display:inline-block;">
+    <!-- $t is vue-i18n global function to translate lang -->
+    <label class="radio-label" style="padding-left:0;">Filename: </label>
+    <el-input :placeholder="$t('excel.placeholder')" v-model="filename" style="width:340px;" prefix-icon="el-icon-document"/>
+  </div>
+</template>
+
+<script>
+export default {
+  props: {
+    value: {
+      type: String,
+      default: ''
+    }
+  },
+  computed: {
+    filename: {
+      get() {
+        return this.value
+      },
+      set(val) {
+        this.$emit('input', val)
+      }
+    }
+  }
+}
+</script>