feat: enable direct GitHub consumption without npm publishing

[amanabiy]

Description

This PR enables direct GitHub consumption of build-tools, eliminating the need for npm publishing.

Changes

The changes in this PR are as the following renamed the /src folder to /lib, and exported the /lib as . in package.json to make it accessible without any change in the consumers. The other change is to stop publishing the repository, and make the prebuild, build, and postbuild commands echoing for now as we are skipping them as we are not doing anything.

Deployment Strategy

⚠️ Do not merge immediately after approval

1. First, update all consuming repositories to use the GitHub dependency: @cloudscape-design/build-tools": "github:cloudscape-design/build-tools#transition-main-do-not-edit
2. Then we can create another similar PR to be merged to main, and update all the other dependencies to consume from the main branch.

Testing

Validated GitHub consumption in draft PRs across all dependent repositories:

1. components (PR) - PR
2. chat-components (PR) - PR
3. chart-components (PR) - PR
4. board-components (PR) - PR
5. code-view (PR) - PR

Related links, issue #, if available: n/a

How has this been tested?

Review checklist

The following items are to be evaluated by the author(s) and the reviewer(s).

Correctness

• Changes include appropriate documentation updates.
• Changes are backward-compatible if not indicated, see CONTRIBUTING.md.
• Changes do not include unsupported browser features, see CONTRIBUTING.md.
• Changes were manually tested for accessibility, see accessibility guidelines.

Testing

• Changes are covered with new/existing unit tests?
• Changes are covered with new/existing integration tests?

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[pan-kot]

Let's remove prebuild and postbuild

[amanabiy]

Makes sense, I will remove them.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 0.00%. Comparing base (aa74034) to head (db271d5).
⚠️ Report is 1 commits behind head on main.

❌ Your project status has failed because the head coverage (0.00%) is below the target coverage (90.00%). You can increase the head coverage or adjust the target coverage.

Additional details and impacted files

@@           Coverage Diff            @@
##             main   #25       +/-   ##
========================================
- Coverage   91.96%     0   -91.97%     
========================================
  Files           5     0        -5     
  Lines         112     0      -112     
  Branches       36     0       -36     
========================================
- Hits          103     0      -103     
+ Misses          9     0        -9     

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