feat(console): DKIM, DMARC & SPF records for custom domains

[betimshahini]

For OTP emails originating from custom domains, we need to have DKIM, DMARC and SPF records configured correctly on the customer's DNS configuration so that OTP emails are treated well by the receivers.

These records will need to be exposed in Console as part of the Custom domain configuration screen.
Same DKIM public key that's currently in use for Rollup OTP emails can be used for custom domains as well.

[maurerbot]

• disable pre validation fields after validated (don't show copy icons)
• fix copy icons squeeze on long values
• show transition animation during refresh
• show CNAME key value
• drop spf? set spf records to passport domains