feat: Agent, country visuals

See merge request !83

feat: Assignment UI&backend improvements (create, update)

See merge request !76

thanks for help Tomas Bilos @tbilos

feat: Visuals cleanup

Closes #50, #48, and #45

See merge request !81

feat: create agent

See merge request !79

feat: Theme

See merge request !78

feat: login error message

See merge request !77