[Task] Add license check (STANDARD minimum) to /api/es/search and /api/es/raw

Context

This task was filed as part of the backend API audit spike #35369 (child of #34733).

Problem

render.jsp (line 35) enforces LicenseLevel.STANDARD minimum before rendering the ES Search portlet UI. However, the REST endpoints POST /api/es/search and POST /api/es/raw in ESContentResourcePortlet.java perform no license check. An authenticated API client can call these endpoints directly regardless of the instance's license level.

File

dotCMS/src/main/java/com/dotcms/rest/elasticsearch/ESContentResourcePortlet.java

Expected behavior

Both POST /api/es/search and POST /api/es/raw should return HTTP 402 when the instance license level is below LicenseLevel.STANDARD, matching the portlet gate in render.jsp.

Implementation notes

• Use LicenseUtil.getLevel() and compare against LicenseLevel.STANDARD.level (same pattern as render.jsp:35)
• Return Response.status(402).entity("...license required...").build() early
• This is a behavior change — no annotation-only fix possible
• The 402 response is already documented in the OpenAPI spec (added in #35369 spike)

Out of scope

• Do NOT change behavior of the GET variants (they are @Hidden and excluded from the public spec)
• Do NOT change any other endpoint behavior

Parent issues

• Audit spike: #35369
• BE API umbrella: #34292
• Epic: #34733

Start with dotCMS/src/main/java/com/dotcms/rest/elasticsearch/ESContentResourcePortlet.java and compare the endpoint flow with the LicenseUtil.getLevel() gate in render.jsp. Confirm that POST /api/es/search and POST /api/es/raw return HTTP 402 below LicenseLevel.STANDARD, while GET variants and other endpoint behavior remain unchanged.