Improved script portability by switching to `/usr/bin/env bash`, ensuring
better support across environments where `bash` may not be the default shell.
Refactored ClusterSecretStore and ExternalSecret deployment to support
VaultWarden custom fields beyond login/password, including multi-line
values via file input. Also made the secret template name configurable
for added flexibility.
ClusterSecretStore are supposed to be cluster-wide objects, it's useless
to precise any namespace.
Existing make command wasn't working on Mac. Fixed it, plus
refactored it in a proper script, so we can share it among
projects, as for the build kind cluster one.
External secrets are created in a dedicated namespace, to avoid
duplicating them if we spawn several LaSuite applications on the
same local stack.
