fix: allow user defined tls variables to be set instead of hardcoded default values

[khawarizmus]

Currently using the role variables as such

vault_transit_tls_ca_cert: "vault-transit-ca-chain.crt"
vault_transit_tls_client_cert: "vault-autounseal.crt"
vault_transit_tls_client_key: "vault-autounseal.key"

Will totally ignore the values and will always yield the following config. the jinja template looks fine but the issue is that the variables are overridden by the defaults as you can see below

seal "transit" {
  //... stuff here
  
  // TLS Configuration
  tls_ca_cert        = "/etc/vault.d/tls/supporting-ca-chain.crt"
  tls_client_cert    = "/etc/vault.d/tls/autounseal_client_cert.pem"
  tls_client_key     = "/etc/vault.d/tls/autounseal_client_key.pem"
}

This pr fixes this

[lakrass]

The changes itself lgtm! :)
Can you please reword your commit messages using conventional commits and rebase your branch? Then I'll approve the PR.

[khawarizmus]

@lakrass I have done as requested. didn't realize that commit didn't follow convention.