* Introduces new configuration variables for OIDC:
- GRIST_OIDC_IDP_ENABLED_PROTECTIONS
- GRIST_OIDC_IDP_ACR_VALUES
- GRIST_OIDC_IDP_EXTRA_CLIENT_METADATA
* Implements all supported protections in oidc/Protections.ts
* Includes a better error page for failed OIDC logins
* Includes some other improvements, e.g. to logging, to OIDC
* Adds a large unit test for OIDCConfig
* Adds support for SERVER_NODE_OPTIONS for running tests
* Adds to documentation/develop.md info about GREP_TESTS, VERBOSE, and SERVER_NODE_OPTIONS.
