Need to update name validation when creating a cluster to match rules from the Backend

[eva-vashkevich]

Steps to reproduce:

1. Start creating a new cluster
2. Enter "test_test" as a name
3. Fill in other required fields and press 'Create'
4. "Cluster.cluster.x-k8s.io "test_test" is invalid: metadata.name: Invalid value: "test_test": a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is 'a-z0-9?(.a-z0-9?)*') is thrown

Expected behavior:
Validation should not allow values that do not conform to this rule.