fix: use consistent Dns casing in operation IDs

[kadhirash]

Addresses #580

Changes getDNSForSite to getDnsForSite and configureDNSForSite to configureDnsForSite to match the naming convention used by all other Dns-related operations (e.g., getDnsZone, createDnsZone, deleteDnsZone, etc.).

This ensures consistent camelCase naming across the API and prevents confusion when switching between different Dns-related methods.

Changes:

• Updated 2 operation IDs in swagger.yml
• All tests passing ✅

Note:

• The Go client files will need to be regenerated by maintainers after merge (as mentioned in CONTRIBUTING.md).