feat: supporting tag color with external mapping file

[elminsterjimmy]

• supporting tag color with external mapping file.
• supporting color for sub tags.

[elminsterjimmy]

Taskido supports tag color by rewrite the tag name with the color code, which is not graceful, I have modified the dataview script to support external tag color mapping.

The tag color mapping file has a key /value format that looks like:

{
    "work": "#ff9d0a",
    "math": "#30d158",
    "personal": "#66d4cf",
    "obsidian": "#ffd60a",
    "plan": "#0a84ff"
}