Add template command

[strokyl]

All the time I use the cli, I found hard to bootstrap my yaml file for resource. The idea of this PR is to extract example from the openapi.
Here a usage example:

╭─lduzan@duzan ~/code/ctl ‹propose_template› 
╰─$ conduktor template                                                                                                                                                1 ↵
Get a yaml example for a given kind

Usage:
  conduktor template [flags]
  conduktor template [command]

Available Commands:
  Alert                         Get a yaml example for resource of kind Alert
  AliasTopic                    Get a yaml example for resource of kind AliasTopic
  Application                   Get a yaml example for resource of kind Application
  ApplicationGroup              Get a yaml example for resource of kind ApplicationGroup
  ApplicationInstance           Get a yaml example for resource of kind ApplicationInstance
  ApplicationInstancePermission Get a yaml example for resource of kind ApplicationInstancePermission
  ConcentrationRule             Get a yaml example for resource of kind ConcentrationRule
  Connector                     Get a yaml example for resource of kind Connector
  GatewayGroup                  Get a yaml example for resource of kind GatewayGroup
  GatewayServiceAccount         Get a yaml example for resource of kind GatewayServiceAccount
  Group                         Get a yaml example for resource of kind Group
  IndexedTopic                  Get a yaml example for resource of kind IndexedTopic
  Interceptor                   Get a yaml example for resource of kind Interceptor
  KafkaCluster                  Get a yaml example for resource of kind KafkaCluster
  KafkaConnectCluster           Get a yaml example for resource of kind KafkaConnectCluster
  KsqlDBCluster                 Get a yaml example for resource of kind KsqlDBCluster
  ServiceAccount                Get a yaml example for resource of kind ServiceAccount
  Subject                       Get a yaml example for resource of kind Subject
  Topic                         Get a yaml example for resource of kind Topic
  TopicPolicy                   Get a yaml example for resource of kind TopicPolicy
  User                          Get a yaml example for resource of kind User
  VirtualCluster                Get a yaml example for resource of kind VirtualCluster

Flags:
  -f, --file string   Write example to file
  -h, --help          help for template

Global Flags:
      --permissive   permissive mode, allow undefined environment variables
  -v, --verbose      show more information for debugging

Use "conduktor template [command] --help" for more information about a command.
╭─lduzan@duzan ~/code/ctl ‹propose_template› 
╰─$ conduktor template KafkaCluster                                                                                                                                   1 ↵
apiVersion: v2
kind: KafkaCluster
metadata:
    name: my-kafka-cluster
    labels:
        env: prod
spec:
    displayName: yo
    bootstrapServers: localhost:9092
    properties:
        sasl.jaas.config: org.apache.kafka.common.security.plain.PlainLoginModule required username="admin" password="admin-secret";
    color: '#FF0000'
    icon: icon
    schemaRegistry:
        url: https://my-schema-registry:8081
        security:
            username: admin
            password: admin-secret
            type: BasicAuth
        ignoreUntrustedCertificate: false
        type: ConfluentLike

╭─lduzan@duzan ~/code/ctl ‹propose_template› 
╰─$ conduktor template Topic -f topic.yaml
╭─lduzan@duzan ~/code/ctl ‹propose_template●› 
╰─$ cat topic.yaml 
apiVersion: v2
kind: Topic
metadata:
    name: my-topic
    cluster: my-cluster
    labels:
        conduktor.io/application: application-a
        conduktor.io/application-instance: staging
        user-labels: I am a user label
    catalogVisibility: PUBLIC
    descriptionIsEditable: true
    description: This is a topic description
    sqlStorage:
        retentionTimeInSecond: 42
spec:
    partitions: 1
    replicationFactor: 1
    configs:
        cleanup.policy: delete
        retention.ms: '86400000'
╭─lduzan@duzan ~/code/ctl ‹propose_template●› 
╰─$ conduktor template Topic -f topic.yaml
File topic.yaml already exists