feat: add BundID password login flow model (!15) · Merge requests · Föderale IT-Kooperation (FITKO) / Matrix-based G2X communication („Neo“) / Solution architecture · GitLab

Issue: planning#36

This MR

adds scaffolding for a structurizr model
models just the components and their relationships on a high level to depict the citizen's (password-based) login flow with BundID
creates a dynamic view of this flow, particularly one that can be rendered to a mermaidjs sequence diagram