broker tries to reconnect to db in case of problems, refactoring code

CMakeModules/prepare_asapo.cmake

broker/src/asapo_broker/database/mongodb.go

broker/src/asapo_broker/database/mongodb_test.go

broker/src/asapo_broker/server/process_request.go

broker/src/asapo_broker/server/process_request_test.go

broker/src/asapo_broker/server/request_common.go

broker/src/asapo_broker/server/server.go

broker/src/asapo_broker/server/server_test.go

config/nomad/nginx_kill_lin.nmd

config/nomad/nginx_kill_win.nmd

consumer/api/cpp/include/consumer/consumer_error.h

consumer/api/cpp/unittests/test_server_broker.cpp

examples/consumer/getnext_broker/check_linux.sh

examples/consumer/getnext_broker/check_windows.bat

examples/consumer/getnext_broker/getnext_broker.cpp

examples/consumer/getnext_broker_python/check_linux.sh

examples/consumer/getnext_broker_python/check_windows.bat

examples/pipeline/in_to_out/check_linux.sh

examples/pipeline/in_to_out/check_windows.bat

examples/pipeline/in_to_out_python/check_linux.sh