chore: add commitlint to enforce commit structure

[frederikprijck]

This PR adds commitlint for both locally and on CI. The goal here is to enforce conventional commits throughout all the commits, which has t he following benefits:

• Automated Changelog Generation: This is the biggest win. Tools can parse these messages and instantly generate a beautiful, categorized changelog. The manual step in our "ship" tool is completely eliminated.

• Clearer Git History: The history becomes a high-level story of the project's evolution. Anyone can scan the commit log and immediately understand the nature of each change without reading the code.

• Automatic Semantic Versioning: The commit type directly maps to Semantic Versioning rules (fix = PATCH bump, feat = MINOR bump, feat! or BREAKING CHANGE: = MAJOR bump). This removes the guesswork from versioning.

• Improved Code Review: It encourages developers to create smaller, more focused PRs. A PR should ideally contain commits of a similar type, making it easier for reviewers to understand its purpose.

• Enabling Powerful Tooling: It unlocks an entire ecosystem of tools, including the one we will propose next: release-please.

This PR adds integration in different cases:

• An Husky hook to ensure we only commit valid commit messages
• A GitHub action to verify the PR title is using a valid title (this implies that we need to ensure we only allow squash and merge)
• A GitHub action to verify the master branch by verifying the commit message on merging

[developerkunal]

LGTM