FHIR Pacage Cache is case-sensitive

Describe the bug

As discussed in org.hl7.fhir.core issues #475, the FHIR validator was until recently treating package IDs as case-sensitive, leading to problems when packages declared dependencies with another capitalization. The proposed solutions is to always treat the IDs as lowercase (ignore casing). However, when a package is added to the JpaPackageCache, a case-sensitive package ID check is performed, leading to the issue described in the linked issues. Specifically, the check is in the method JpaPackageCache#addPackageToCache

To Reproduce
Steps to reproduce the behavior:

1. Set up a HAPI JPA server using the JPA starter project
2. Configure the server to load dependencies on start-up (as discussed in this Zulip thread
3. Configure the server to load the de.gecco#1.0.3 FHIR package on start-up (in application.yaml)
4. Start the server

The error occurs when loading one of the dependencies - log output will this:

2021-05-26 16:52:02.919 [main] INFO  c.u.f.jpa.packages.JpaPackageCache [JpaPackageCache.java:195] Parsing package .tar.gz (28612 bytes) from http://packages.fhir.org/kbv.basis/1.1.3
2021-05-26 16:52:02.948 [main] ERROR o.a.c.c.C.[Tomcat].[localhost].[/] [DirectJDKLog.java:175] Servlet.init() for servlet [jpaRestfulServer] threw exception
ca.uhn.fhir.rest.server.exceptions.InvalidRequestException: Package ID KBV.Basis doesn't match expected: kbv.basis
    at ca.uhn.fhir.jpa.packages.JpaPackageCache.addPackageToCache(JpaPackageCache.java:199)
    at ca.uhn.fhir.jpa.packages.JpaPackageCache.loadPackage(JpaPackageCache.java:398)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:344)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:208)
    at com.sun.proxy.$Proxy213.loadPackage(Unknown Source)
    at ca.uhn.fhir.jpa.packages.PackageInstallerSvcImpl.fetchAndInstallDependencies(PackageInstallerSvcImpl.java:265)
    at ca.uhn.fhir.jpa.packages.PackageInstallerSvcImpl.fetchAndInstallDependencies(PackageInstallerSvcImpl.java:268)

Expected behavior
The package should load without issues, regardless of casing.

Environment (please complete the following information):

• HAPI FHIR Versios: Latest build
• OS: iOS

[patrick-werner]

fixed by #2683