cc-block: refactor and introduce slot stack

[hsablonniere]

Context

We want to refactor the cc-block component with a new structure based on slot stack (see #151 and #108) .

Here is a list of all the components we want to use the new cc-block in.

DONE (or almost done)

• [x] cc-env-var-form
• [x] cc-header-addon
• [x] cc-header-orga
• [x] cc-ssh-key
• [x] cc-tcp-redirection-form
• [x] cc-addon-admin
• [x] cc-addon-credentials
• [x] cc-addon-linked-apps
• [x] cc-addon-option-form
• [x] cc-addon-features
• [x] cc-elasticsearch-info
• [x] cc-email-list
• [x] cc-heptapod-info
• [x] cc-invoice-list
• [x] cc-invoice
• [x] cc-jenkins-info
• [x] cc-matomo-info
• [x] cc-orga-member-list
• [x] cc-grafana-info
• [x] cc-header-app
• [x] cc-addon-backups
• [x] cc-domain-management

TO DO

[hsablonniere]

https://github.com/CleverCloud/clever-components/issues/151

[florian-sanders-cc]

About the visibility toggle, in the next version, we should avoid adding a click event on the whole title area and handling keyboard only with the button element inside:

• This breaks automatic a11y testing (sees a click event without a key handler),
• In these cases, we need to implement the ARIA disclosure pattern anyway.