feat: ep theme (#156)

* feat: ep-theme

* perf: ep-theme

Co-authored-by: lrl <742798240@qq.com>

package.json

@@ -40,6 +40,7 @@
     "animate.css": "^4.1.1",
     "axios": "^0.21.1",
     "cropperjs": "^1.5.11",
+    "css-color-function": "^1.3.3",
     "dayjs": "^1.10.7",
     "echarts": "^5.2.1",
     "element-plus": "1.2.0-beta.6",
@@ -56,6 +57,7 @@
     "remixicon": "^2.5.0",
     "resize-observer-polyfill": "^1.5.1",
     "responsive-storage": "^1.0.11",
+    "rgb-hex": "^4.0.0",
     "v-contextmenu": "3.0.0",
     "vue": "^3.2.24",
     "vue-i18n": "^9.2.0-beta.3",