Use Bootstrap theme

[mroest]

In order to create a consistent look and feel for all the GSSP plugins the UI is updated to use the bootstrap framework.

Other changes:

• Removed language selector. Language selection is handled by Stepup Gateway
• Upgrade symfony / flex recipes to support composer 2.0
• Upgrade CSS / JS dependencies to resolve encore compat issues and recent security vulns

[phavekes]

Production build fails on :

[vagrant@stepup-build /vagrant]$ /usr/bin/php72 /usr/local/bin/composer install --prefer-dist --ignore-platform-reqs --no-dev --no-interaction --optimize-autoloader
Installing dependencies from lock file
Verifying lock file contents can be installed on current platform.

  [ErrorException]                                           
  constant(): Couldn't find constant SODIUM_LIBRARY_VERSION 

Travis build has issues too:

> symfony-cmd
sh: 1: symfony-cmd: not found
Script symfony-cmd handling the auto-scripts event returned with error code 127
Script @auto-scripts was called via post-install-cmd
The command "composer install" failed and exited with 127 during .

Could you take a look at this?

[mroest]

I'm not terribly stoked on all the changes from the updated recipes, but that is the price you pay for using a framework in all its glory I guess.

Yes, i could leave it out but next time you update recipes it will be much worse and time consuming to figure out what needs to stay or go...