Add global default format options

[lukeed]

Is your feature request related to a problem? Please describe.

I can configure this extension to be my global TS/JS/etc formatter; eg

// global user vscode settings
"[typescript]": {
  "editor.formatOnSave": true,
  "editor.defaultFormatter": "denoland.vscode-deno",
},

With this, Deno will format everything, even without the presence of a deno.jsonc? file in the project (#780)

However, because there is no config file, when the extension runs deno fmt all its defaults are applied. I know I can add a config file, but I'm looking to have vscode global defaults across all projects/scripts... until the project carries its own formatting configuration.

Describe the solution you'd like

The vscode extension to accept a fmt configuration block, that only applies when there is no other Deno configuration found.

This could be a raw JSON blob, or individual settings like what Prettier does.