Replace coloris with vanilla-colorful (#30201)

Found [a better color
picker](https://github.com/web-padawan/vanilla-colorful) that [does not
rely](https://github.com/mdbassit/Coloris/issues/139) on
`querySelectorAll` or a global shared instance, and is also around a
third of the size of the previous one.

The popover is handled by tippy.js for which I introduced a new "bare"
theme and it uses a new sibling-based mechanism which should prove
useful later to create tippy popovers via HTML only.

<img width="846" alt="Screenshot 2024-03-31 at 04 03 38"
src="https://github.com/go-gitea/gitea/assets/115237/7639b911-a2d7-4f5c-bffd-a9d84561e747">

package.json

@@ -12,7 +12,6 @@
     "@github/relative-time-element": "4.4.0",
     "@github/text-expander-element": "2.6.1",
     "@mcaptcha/vanilla-glue": "0.1.0-alpha-3",
-    "@melloware/coloris": "0.23.0",
     "@primer/octicons": "19.9.0",
     "add-asset-webpack-plugin": "2.0.1",
     "ansi_up": "6.0.2",
@@ -53,6 +52,7 @@
     "toastify-js": "1.12.0",
     "tributejs": "5.1.3",
     "uint8-to-base64": "0.2.0",
+    "vanilla-colorful": "0.7.2",
     "vue": "3.4.21",
     "vue-bar-graph": "2.0.0",
     "vue-chartjs": "5.3.0",