change(cred-libs): Update user_password to username_password

[louisruch]

Creating a new cred library with user_password fails:

boundary credential-libraries create vault -credential-store-id $CRED_STORE_ID -vault-path "secret/data/my-secret" -name "Super secret lib" -credential-type user_password
Error from controller when performing create on vault-type credential library

Error information:
  Kind:                InvalidArgument
  Message:             Error in provided request.
  Status:              400
  context:             Error from controller when performing create on vault-type credential library

  Field-specific Errors:
    Name:              -credential-type
      Error:           Unknown credential type "user_password"

Creating a new cred library with username_password:

boundary credential-libraries create vault -credential-store-id $CRED_STORE_ID -vault-path "secret/data/my-secret" -name "Super secret lib" -credential-type username_password

Credential Library information:
  Created Time:          Wed, 08 Jun 2022 15:19:20 PDT
  Credential Store ID:   csvlt_VlFgkW6EGX
  ID:                    clvlt_gJUfsRyyFR
  Name:                  Super secret lib
  Type:                  vault
  Updated Time:          Wed, 08 Jun 2022 15:19:20 PDT
  Version:               1

  Scope:
    ID:                  p_1234567890
    Name:                Generated project scope
    Parent Scope ID:     o_1234567890
    Type:                project

  Authorized Actions:
    no-op
    read
    update
    delete

  Attributes:
    HTTP Method:         GET
    Path:                secret/data/my-secret

  Credential Type:
    username_password

Connecting to target:

boundary connect -target-id ttcp_1234567890

Proxy listening information:
  Address:             127.0.0.1
  Connection Limit:    -1
  Expiration:          Wed, 08 Jun 2022 23:20:29 PDT
  Port:                50861
  Protocol:            tcp
  Session ID:          s_dkx9C3MJ8L

  Credentials:
    Credential Source ID:   clvlt_gJUfsRyyFR
    Credential Source Name: Super secret lib
    Credential Store ID:    csvlt_VlFgkW6EGX
    Credential Store Type:  vault
    Credential Type:        username_password
    Secret:
          password:   pass
          username:   test

Curl string output

boundary credential-libraries create vault -credential-store-id $CRED_STORE_ID -vault-path "secret/data/my-secret" -name "Super secret lib" -credential-type username_password -output-curl-string

curl -X POST -H "Authorization: Bearer $(boundary config get-token -keyring-type keychain -token-name default)" -H "Content-Type: application/json" -d '{"attributes":{"path":"secret/data/my-secret"},"credential_store_id":"csvlt_VlFgkW6EGX","credential_type":"username_password","name":"Super secret lib"}' 'http://127.0.0.1:9200/v1/credential-libraries'

[louisruch]

@ddebko PTAL

[ddebko]

LGTM

[tmessi]

I think your commit prefix should be refact not change.