feat(helmsman): replace generic apitestrig/uitestrig charts with eSignet's own for esignet-standalone-2.0.0 #392

Summary

Replace the generic mosip/apitestrig/mosip/uitestrig charts in the
esignet-standalone-2.0.0 profile's testrigs-dsf.yaml with eSignet's own
dedicated testrig charts, translated from eSignet's reference deploy scripts:

• esignet-apitestrig/install.sh → mosip/esignet-apitestrig (Go harness)
• esignet-uitestrig/install.sh → mosip/esignet-uitestrig (Java harness)

Previously testrigs-dsf.yaml for this profile was an unmodified copy-paste of
the esignet-standalone (1.0/Java) profile's generic-chart config — it never
actually used eSignet 2.0.0's own testrig charts.

Scope

• testrigs-dsf.yaml: 3 apitestrig apps (esignet-mock/esignet-mosipid/esignet-sunbird,
  each in the eSignet instance's own namespace) now use mosip/esignet-apitestrig
  2.0.0 with the correct configFile per instance (config.mock/mosip/sunbird.json).
• 3 new uitestrig apps use mosip/esignet-uitestrig 2.0.0, each in its own
  namespace (esignet-uitestrig/esignet-mosipid-uitestrig/esignet-sunbird-uitestrig),
  matching install.sh's own NS/SOURCE_NS split — uitestrig for eSignet itself
  didn't exist in this profile before.
• Only esignet-mosipid (the only instance backed by a real IDA identity) gets
  real test-identity/onboarding values; esignet-mock/esignet-sunbird need none.
• KEYCLOAK_CLIENT_SECRET/consent DB password reuse this repo's existing
  PMS_CLIENT_SECRET_VALUE/db-common-secrets conventions rather than inventing
  new secret-provisioning mechanisms.
• helmsman_testrigs.yml: new required Environment secrets/vars for the
  mosipid-only test identity plus a shared UI-testrig OIDC client, validated
  up front with a clear error listing what's missing.
• docs/HELMSMAN_TESTRIGS_GUIDE.md updated to document all of the above.

Report storage uses reports.persistence (PVC) rather than reports.s3 — no
established MinIO bucket convention exists yet for these charts in this repo.

Status

Implemented and pushed to the es-go-test branch (commit 83e8ab6c), part of
PR #311. Leaving this open until merged and until the required Environment
secrets are actually provisioned and a real deploy is verified — overlaps with
#391 (apitestrig validation), which should also exercise the new uitestrig apps.

References

• Parent: feat(helmsman): add isolated esignet-standalone-2.0.0 profile #302
• Implementation: Add esignet-standalone-2.0.0 profile (Go eSignet) support #311 (commit 83e8ab6c)
• Related: test: validate apitestrig suite against esignet-standalone-2.0.0 #391