Validate correspondance between load statement and environment configuration

[CThuleHansen]

The environment file may specify FMU paths that from an expansion perspective should corespond to the FMUs in the load statements in the initial specification. However there should be an initial check making sure that identifiers assigned from load expressions and which is present in the environment also specifies the same FMU.

Currently it is possible to misconfigure the environment and spec file so one FMU is used during expansion and another is loaded at runtime.