Remove @eval from @RemoteFile macro call

[disberd]

This should fix the way the @RemoteFile macro is called inside the get_iers_eop subfunctions to remove calls to the @eval macro.

The use of @eval is not needed since @RemoteFile has proper macro hygiene and also causes pre-compilation errors when using SatelliteToolbox as dependency and calling get_iers_eop in another Package, see issue #75.

The use of @eval was put here probably because @RemoteFile has two signatures, one that takes a symbol as first argument (used to get the name of the variable name to assign the output to), and another that does not and simply return th output of the RemoteFile call.

Two possible solutions are possible:

1. Keep using the macro and switch to the correct version without @eval, giving the name _eop_iau2000A (or _eop_iau1980) as additional first argument. This may make the code a bit less clear as there is not a visible assignment to the variable
2. Directly skip the macro to keep the assignment clear in the code and use the underlying call to the RemoteFile function. This has the drawback that the directory where to download the file (which is automatically computed from the macro) has to be put in the code.

I chose the first approach here as it was the one with less friction, but I am willing to change this PR to use the 2nd approach.

[ronisbr]

Hi @disberd !

Perfect, thanks for the PR.