Add gladia transcription

[HugoGresse]

• add a new public page with a user defined password to display the Gladia live transcription using the user microphone

Some details:

• display a a public page, ask the user a password chich he will have defined previously in the event setting, let him selected the track and will match the ongoing or upcoming session.
• end goal is to have a transcription_hint retrieved automatically from OpenPlanner. The current implementation does retrieve the talk from the selected track but does not use anything useful here.
• having a specific API route for that was needed to have a somewhat protected Gladia API Key user facing without relying on a single OpenPlanner account with wide access.

[github-actions[bot]]

Visit the preview URL for this PR (updated for commit 039a284):

• https://conferencecenterr--pr128-gladia-31cwu7ma.web.app
• https://apiopenplanner--pr128-gladia-gzl6acao.web.app

_{(expires Sun, 07 Jul 2024 13:54:00 GMT)}

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