200 move to pnpm

[joao-m-santos]

Relates to #200

📝 Description

Switch from npm + nx to pnpm in order to fix Storybook's dependency problems and the fact that npm doesn't support not hoisting dependencies.

Context:

• Investigate a way to develop and test components on both Vue versions #200
• [Bug]: Storybook 7 migration not sucessful in monorepo storybookjs/storybook#21710
• [RRFC] Add nohoist option for workspaces npm/rfcs#287

Findings:

• pnpm works faster, especially in a Docker container
• Dependencies declared in package.json are better-structured - fully scoped for each workspace
• pnpm allows for running commands in parallel, plus its great workspaces support removes need for nx, thus reducing architecture complexity

💥 Is this a breaking change (Yes/No):

• No
• Yes (please describe the impact and migration path for existing Lume users)

📝 Additional Information

This PR is only to be merged after a decision is made between pnpm and yarn. Until then it serves as an example of the pnpm implementation in the existing project.

Before submitting the PR, please make sure you do the following

• Read the Contributing Guidelines.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.

[joao-m-santos]

Closed by #257