add vault user & admin entities and policies

See merge request platform-one/big-bang/apps/sandbox/vault!13

Add CHANGELOG.md file

See merge request platform-one/big-bang/apps/sandbox/vault!8

Kustomization

See merge request platform-one/big-bang/apps/sandbox/vault!5

Dev

See merge request platform-one/big-bang/apps/sandbox/vault!4

Staging to dev

See merge request platform-one/big-bang/apps/sandbox/vault!3

Staging

See merge request platform-one/big-bang/apps/sandbox/vault!2

# Conflicts:
#   chart/CHANGELOG.md
#   chart/Chart.yaml
#   chart/templates/_helpers.tpl
#   chart/templates/injector-deployment.yaml
#   chart/templates/server-statefulset.yaml
#   chart/test/README.md
#   chart/test/acceptance/server-ha-enterprise-dr.bats
#   chart/test/acceptance/server-ha-enterprise-perf.bats
#   chart/test/chart/verifier.bats
#   chart/test/unit/injector-deployment.bats
#   chart/test/unit/server-ha-disruptionbudget.bats
#   chart/test/unit/server-statefulset.bats
#   chart/test/unit/ui-service.bats
#   chart/values.schema.json
#   chart/values.yaml

Infra

See merge request platform-one/big-bang/apps/sandbox/vault!1