Akamai Edge DNS - Support for "Account Switch Key" in DNS01 Solver

[Aransh]

Is your feature request related to a problem? Please describe.
We are using cert-manager with the Akamai DNS01 solver for issuing certificates. Our Akamai setup requires us to use an "account switch key" to interact with the Akamai Edge DNS API. Currently, cert-manager does not support passing an "account switch key" to the Akamai API.

Describe the solution you'd like
We would like cert-manager to support the Akamai "account switch key" in the DNS01 solver. This could be implemented as a new field in the AkamaiDNS01Solver struct, similar to the existing clientTokenSecretRef, clientSecretSecretRef, and accessTokenSecretRef fields. The Akamai client configuration in the DNS01 solver should be updated to use this new field.

From my experience, this parameter is able to be passed using the .edgerc file under "account_key", or in api calls as "accountSwitchKey".

Describe alternatives you've considered
We considered passing the "account switch key" as an environment variable to the cert-manager pod, but this is not a viable solution because the DNS01 solver gets its configuration from the Issuer or ClusterIssuer resource, not from environment variables in the pod.

Additional context
The "account switch key" is a feature of the Akamai Edge DNS API that allows clients to switch between different Akamai accounts. This is required in some Akamai setups.

Environment details (remove if not applicable):

• Kubernetes version: 1.27
• Cloud-provider/provisioner: Linode
• cert-manager version: v1.13.5
• Install method: e.g. Helm/ArgoCD

/kind feature