Schema fixes and Write Flow preview

Fixes

• When creating a Bridge with the newest version of umh-core you previously got a warning for not existing schemas. These are now added.
• Depending on the screen resolution, the toggle-switch appeared slightly misaligned. This issue has been resolved, so the button now appears consistent regardless of the screen resolution.
• Previously, standalone flow names accepted spaces and other characters that cause deployment failures. Names are now validated the same as bridges and stream processors: letters, numbers, dashes, and underscores only

Preview: Disable Read Flow

• Now uses UMH_TOPICS list as input for write flows. Breaks all existing write flows.