feat: module hover tooltip for pnpm catalogs

[mmellado]

PNPM has introduced support for the catalog protocol, which allows us to define dependency versions in pnpm-workspace.yaml under the catalog key. Would be great to be able to get dependency version tooltips in this file as well, to make it easier to check catalog dependency versions all at once.

Example:

pnpm-workspace.yml

packages:
    - 'packages/**/*'

catalog:
    '@types/node': ^20.14.15
    typescript: ^5.5.4

PNPM Catalogs description: https://pnpm.io/catalogs

[tjx666]

I will try to migrate https://github.com/antfu/vscode-pnpm-catalog-lens featue to this extension.
Pr also welcome.