DaCe FPGA backend has a new home!

[tbennun]

We refactored AMD and Intel FPGA code generation and supporting transformations to https://github.com/spcl/dace-fpga
The change will take effect in the main branch and will be released starting with DaCe version v2.0.0-alpha2.

This step was done to ensure the stability of FPGA code generation, to demonstrate the modularity of the framework's infrastructure (showing how new code generators, library node implementations, and transformations can be supported out-of-tree), and to reduce CI turnaround time.

All relevant issues and PRs will be closed and can be reopened in the new repository as necessary.