support regional tiered cache setting

[sbfaulkner]

Current cloudflare-go version

v0.72.0

Description

Cloudflare has introduced regional tiered caching, but the go package doesn't yet support the feature.

Use cases

Make it possible for clients (eg. terraform) to use the API to configure regional tiered caching.

Potential cloudflare-go usage

got, err := client.GetRegionalTieredCache(context.Background(), ZoneIdentifier(testZoneID))

settings := RegionalTieredCacheSettings { Value: "on" }

got, err := client.SetRegionalTieredCache(context.Background(), ZoneIdentifier(testZoneID), settings)

References

https://developers.cloudflare.com/api/operations/zone-cache-settings-get-regional-tiered-cache-setting
https://developers.cloudflare.com/api/operations/zone-cache-settings-change-regional-tiered-cache-setting