Types of changes

• Add Bregman alternated projected gradient solvers for GW and FGW via functions: BAPG_gromov_wasserstein, BAPG_gromov_wasserstein2, BAPG_fused_gromov_wasserstein, BAPG_fused_gromov_wasserstein2

• update example with FGW solvers comparison.

Motivation and context / Related issue

• Keep up with the (F)GW literature.

How has this been tested (if it applies)

• add tests test_BAPG_fgw, test_BAPG_gromov. Modified in place test_entropic_gromov_dtype_device, test_entropic_fgw_dtype_device.

PR checklist

• I have read the CONTRIBUTING document.
• The documentation is up-to-date with the changes I made (check build artifacts).
• All tests passed, and additional code has been covered with new tests.
• I have added the PR and Issue fix to the RELEASES.md file.