Bump Hl7.Fhir.Base from 5.12.2 to 6.0.1

---
updated-dependencies:
- dependency-name: Hl7.Fhir.Base
  dependency-version: 6.0.1
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

src/Spark.Engine/Spark.Engine.csproj

@@ -15,6 +15,7 @@
 
     <ItemGroup>
         <PackageReference Include="Fhir.Metrics" Version="1.3.1" />
+        <PackageReference Include="Hl7.Fhir.Base" Version="6.0.1" />
         <PackageReference Include="Hl7.Fhir.R4" Version="5.12.2" />
     </ItemGroup>
 

src/Spark.Mongo/Spark.Mongo.csproj

@@ -10,7 +10,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="Hl7.Fhir.Base" Version="5.12.2" />
+        <PackageReference Include="Hl7.Fhir.Base" Version="6.0.1" />
         <PackageReference Include="MongoDB.Driver" Version="3.5.0" />
     </ItemGroup>