Add cookie banner

[louis-md]

Context

This PR adds the cookie banner to the docs

Tests passing before merging the PR:

• The banner opens and closes correctly
• All the checkboxes work correctly and keep the state when the banner is closed/opened
• The local storage of the browser has the right data everytime checkboxes are checked/uncheked
• Compatibility with app.safe.global local storage (staging)

[germartinez]

Tests should be run before merging this PR.
staging env: https://docs.staging.5afe.dev

Some checks to consider:

• The banner opens and closes correctly
• All the checkboxes work correctly and keep the state when the banner is closed/opened
• The local storage of the browser has the right data everytime checkboxes are checked/uncheked
• Compatibility with app.safe.global local storage (staging)

Updated the PR description

[louis-md]

Tests should be run before merging this PR. staging env: https://docs.staging.5afe.dev

Some checks to consider:

• The banner opens and closes correctly
• All the checkboxes work correctly and keep the state when the banner is closed/opened
• The local storage of the browser has the right data everytime checkboxes are checked/uncheked
• Compatibility with app.safe.global local storage (staging)

Updated the PR description

I think we have to merge to test it in staging environment right?

[germartinez]

I found a little issue following this steps:

1. The localStorage is empty
2. The banner is displayed automatically and the user clicks on "Accept All"
3. The user clicks on "Preferences" and the banner is displayed with the "Analytics" checkbox checked.
4. The user unchecks the checkbox and clicks on "Accept All"
5. The user clicks on "Preference" and the banner is displayed, but the checkbox is unchecked and it should be checked. The localStorage works correctly, but not the checkbox.
6. Refreshing the page fixes the issue after step 5.

Edit:
I found that this is also happening at htts://safe.global. As it is just a UI issue happening on the first visit (fixed after refreshing once) and the localStorage works good, I'm fine leaving this as it is for now an not spending more time (unless is something super easy to fix).

[louis-md]

Latest commit makes two changes:

• Fixes small state error found by @germartinez
• Add rel='noreferrer' to _blank target link for security reasons