Update bindings overview picture

[MakisH]

• Renames the SolverInterface to precice wherever applicable

• Renames the precice.f03 to precice.f90, assuming https://github.com/precice/fortran-module/pull/17 will get merged and updates the function call example.

• Python bindings:

  • The second commit (current state) shows the bindings as including precice.hpp
  • The first commit shows the bindings as including Participant.hpp instead of precice.hpp (see https://github.com/precice/python-bindings/issues/194)
  • In case you prefer to keep the Participant.hpp, just drop the second commit.

• Does not include Rust bindings (should it already?)

Closes #329.