Enhanced automatic downloading of ADDA binaries

[myurkin]

A few minor issues, related to automatic downloading of ADDA binaries:

• release.zip should be removed after extraction of the archive
• a folder where the binaries are placed should be named by git hash (or release version/tag), not by download time (as now)
• if the user tries to download binaries of exactly the same version as already available locally (was downloaded previously), we should show a message about that. The user can then choose "OK" (do not download anything new) or "Overwrite existing binaries" (as a repair option).
• Allow user to download at least two versions of ADDA: latest stable release (default option) and the version that was tested with that specific version of GUI (this may help if some backward compatibility is lost during further ADDA development).
• allow some indication of downloaded binaries versions (and removing those that are no longer needed).
• allow user to switch binaries versions as sets (seq, mpi, ocl in one go) in addition to current advanced possibility to use different versions for each execution mode.
• if the user manually specifies (types in) a path to one of the ADDA binaries, GUI should immediately verify that the specified file exist. May be even immediately run adda -V and show the resulting version to the right (see ADDA version #14).

[dsmunev]

partially done https://github.com/adda-team/adda-gui/releases/tag/v0.4.1
still actual:

• Allow user to download at least two versions of ADDA: latest stable release (default option) and the version that was tested with that specific version of GUI (this may help if some backward compatibility is lost during further ADDA development).
• allow user to switch binaries versions as sets (seq, mpi, ocl in one go) in addition to current advanced possibility to use different versions for each execution mode.