Decompilation of object or rebased files

Decompilation via RetDec idaplugin gets into troubles if IDA has the file mapped on a different address than RetDec. In such a case, all metadata that come from IDA in config database are wrong when applied on image loaded by RetDec's image loader library.

This happens for object files. E.g. [hello.zip](https://github.com/avast-tl/retdec-idaplugin/files/1674373/hello.zip), where IDA has `main()` on address `0x8000000` and RetDec has it on `0x34`.

The same thing happens if user makes a rebase in IDA. E.g. here [mytest.zip](https://github.com/avast-tl/retdec-idaplugin/files/1674394/mytest.zip), `main()` is at `0x8900180`, but in IDA, we can do _Edit→Segments→Rebase program_ to `0x1000000` and run decompilation.

Solution: Probably get segments mappings from IDA and apply them in RetDec. This might be tricky, since RetDec libraries are probably not ready for it.