Enable additional features by using sessionStorage

Description

Enable flagged features by acting on sessionStorage. For example:

Define a new feature flag

export type AvailableFeature = 'cost'

Open a browser tab with PCUI, then go to the console and type

window.sessionStorage.setItem('additionalFeatures', '["cost"]')

Reload the page and the cost flag will be active!

Repeated the same procedure explained in the description (on Chrome)

[x] I added tests to new or existing code
[ ] I removed hardcoded strings and used react-i18next library (useTranslation hook and/or Trans component), see an example here
[ ] I made sure no sensitive info gets logged at any time in the codebase (see here) (e.g. no user info or details, no stacktraces, etc.)
[ ] I made sure that any GitHub issue solved by this PR is correctly linked
[ ] I checked that infrastructure/update_infrastructure.sh runs without any error
[x] I checked that npm run build builds without any error
[ ] I checked that clusters are listed correctly
[ ] I checked that a new cluster can be created (config is produced and dry run passes)
[ ] I checked that login and logout work as expected

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