feat(`@vtmn/svelte`, `@vtmn/react`, `vtmn/vue`): use `VtmnAlert` as a component

[Tlahey]

Changes description

Svelte part :

• Export the VtmnAlertItem component in order to be used without the VtmnAlert.
• Title / description can be set with a slot
• Change the <p> to <span> in order to be ISO with other frameworks

Svelte / React / Vue :

• Add a new property ariaLabelCloseButton
• Remove the id no really necessary
• Set the timeout property to 0 in order to keep the alert visible

Also checked https://www.w3.org/WAI/ARIA/apg/patterns/alertdialog/examples/alertdialog/ The div with a role alert doesn't need to have a aria-labelledby /describeby

Context

Checklist

• [x] Make sure you are requesting to pull a topic/feature/bugfix branch. Please, don't request directly from your main!
• [x] Check commits & PR names matches our requested structure. It must follow the https://www.conventionalcommits.org pattern.
• [x] Check your code additions will fail neither code linting checks.
• [x] I have reviewed the submitted code.
• [x] I have tested on related showcases.
• [x] If it includes design changes, please ask for a review design-system-core-team-design GitHub team.

Does this introduce a breaking change?

• Yes
• [x] No (checked on the DKT project, the id is not used)

Other information

[thibault-mahe]

hi! thanks for this PR @Tlahey and for pinging me @lauthieb . Everything is ok for me here, the use of the slot is nice and allows the component to be more flexible, without bringing any breaking change. The only mini breaking change is that the aria-label of the close button is no longer set to "Close toast" by default, which you can quickly change if you want @Tlahey.

Okay fo me otherwise.

[Tlahey]

Hello @thibault-mahe I've done the fix on the aria-label ;)