feat: support --(no-)workspace flag for monorepo packages

[Crdzbird]

Description

To add support for Pub Workspaces in our templates, we need to add a boolean workspace flag (can have a ws alias) to add the necessary configuration for the package to look up its parent workspace.

This is the configuration the flag should wrap:

environment:
  sdk: ^3.12.0
resolution: workspace # new configuration to wrap in pubspec.yaml

To add the package to the workspace, there will be another issue created in the CLI project. The scope of this is just adding the configuration for the templates.

Requirements

• All CI/CD checks are passing.
• There is no drop in the test coverage percentage.

Additional Context

#1635

[marcossevilla]

hey @Crdzbird! thanks for opening this issue.

upon reviewing with the team, we believe the monorepo/workspace integration is key in our projects and would like to add more explicit support for pub workspaces in them, so the solution we found to remain compatible with multiple monorepo management tools (like melos) is to add a --(no-)workspace flag to our templates so you can have the default configuration when you create a new module.

as far as adding the newly created module to the existing workspace, we might hold on that one since it involves project analysis and to support it, projects would have to be very opinionated in their structure or we would have to make it as flexible as possible, which is another issue we're facing with #567.

I'll create an issue on the templates repo to support the workspace flag so it's easier to add a new module to a monorepo, we might want to follow up on another issue or POC to tackle how to add the module to the workspace's pubspec.yaml.