Handle Secrets management

[jpraynaud]

Issue

We need to handle long term storage/security for the cryptographic secrets of the Mithril networks (especially for mainnet):

• Genesis Secret Key
• Eras Secret Key
• Cardano Era Address Secret Key

To do

• [x] Creation of the secure access for dev team on VaultWarden (IT Ticket to create)
• [x] Create and save secret keys in VaultWarden
• [x] Create verification keys in Mithril GitHub repository
• [x] Fund Cardano Era Address Secret Key with 100 ADA

Parent Issue

767

[roynakakawa]

Ticket: https://input-output.atlassian.net/servicedesk/customer/portal/2/ITCR-6366?created=true

[roynakakawa]

IT grant me with an IOG account in Vaultwarden. @jpraynaud what should I do with it?