GLSD-20910: Create endpoint to get top level file detail from eacd-file-processor for a given file reference

[finlaypugh07]

Acceptance Criteria
A 'GET /file-detail/:reference' endpoint is created in the new support-routes file (created in GLSD-20951) on the new eacd-file-processor service (built in GLSD-19170) that returns the following fields for the record from the file collection that matches the given file reference:
fileName
reference
creationDateTime
errorCode
errorMessage
fileStatus
lastUpdatedDateTime
requestorEmail
requestorPID
requestorName
downloadUrl
fileMimeType
uploadTimestamp
checksum
size
failureReason
failureMessage
approverEmail
approverPID
approverName
approvalDateTime
totalEntryCount
totalSuccessCount
totalFailureCount
Internal auth is implemented on this new endpoint and configured such that only emac-support-frontend can call it
The following response status codes are implemented:
Http Code Description Error Code Error Message
200 Success A record was found and returned
204 No Content No record found for the requested reference
Relevant tests are implemented for the new functionality

[platops-pr-bot]

• You have multiple routes files conf/support.routes, conf/testOnlyDoNotUseInAppConf.routes using the same package uk.gov.hmrc.eacdfileprocessor.testOnly.controllers, which leads to collision with the reverse routes. Please ensure each routes file refers to a different package.
• uk.gov.hmrc.objectstore:object-store-client-play-30 can be updated to 2.6.0 in project/AppDependencies.scala.

[platops-pr-bot]

• You have multiple routes files conf/support.routes, conf/testOnlyDoNotUseInAppConf.routes using the same package uk.gov.hmrc.eacdfileprocessor.testOnly.controllers, which leads to collision with the reverse routes. Please ensure each routes file refers to a different package.
• uk.gov.hmrc.objectstore:object-store-client-play-30 can be updated to 2.6.0 in project/AppDependencies.scala.

[platops-pr-bot]

• You have multiple routes files conf/support.routes, conf/testOnlyDoNotUseInAppConf.routes using the same package uk.gov.hmrc.eacdfileprocessor.testOnly.controllers, which leads to collision with the reverse routes. Please ensure each routes file refers to a different package.
• uk.gov.hmrc.objectstore:object-store-client-play-30 can be updated to 2.6.0 in project/AppDependencies.scala.

[dsmith2708]

we likely want to add a test in this file for the exact format the Json is being returned in. checking this we're currently seeing something like

{
  "_id" : {
    "$oid" : "6994a038d540b44c4403aee5"
  },
  "reference" : {
    "value" : "08aad019-7f66-4456-8d52-93f12109876f"
  },
  "status" : "failed",
  "requestorPID" : "12345678",
  "requestorEmail" : "test@hmrc.gov.uk",
  "requestorName" : "Test User",
  "details" : {
    "failureReason" : "REJECTED",
    "message" : "MIME type application/pdf is not allowed for service"
  },
  "creationDateTime" : {
    "$date" : {
      "$numberLong" : "1771418638342"
    }
  }
}

Where we want to see something like:

{
  "id" : "6994a038d540b44c4403aee4",
  "reference" : "test-ref-789",
  "status" : "approved",
  "requestorPID" : "12345678",
  "requestorEmail" : "test@hmrc.gov.uk",
  "requestorName" : "Test User",
  "details" : {
    "name" : "bulk-de-enrol.csv",
    "mimeType" : "text/csv",
    "downloadUrl" : "http://localhost:9570/upscan/download/c5da3bd6-f118-4cde-afff-93f763bf6448",
    "size" : 32270,
    "checksum" : "a0acaa6039c1a94c6f5c43f144c5add07de9381f98701cb14c7c6ce2be18020b"
  },
  "approverDetails" : {
    "approverEmail" : "approverTest@hmrc.gov.uk",
    "approverPID" : "12345678",
    "approverName" : "Approver1",
    "errorCode" : "error code",
    "errorMessage" : "error message"
  },
  "totalEntryCount" : 100,
  "uploadedDateTime" : null,
  "lastUpdatedDateTime" : null,
  "approvedAtDateTime" : "2026-02-18T12:43:58.342Z",
  "creationDateTime" : "2026-02-18T12:43:58.342Z",
  "totalFailureCount" : 5,
  "totalSuccessCount" : 95
}

So that the ID, dates etc. are in a more appropriate format