Move source editor out of module (#12457)

* Update Copybara options in preparation for open-sourcing the source editor

* Move files

* Update paths

* Remove source-editor module and checks for its existence

* Explicitly mention CM6 license in files that contain code adapted from CM6

GitOrigin-RevId: 89b7cc2b409db01ad103198ccbd1b126ab56349b

services/web/frontend/js/features/source-editor/utils/position.ts

@@ -0,0 +1,19 @@
+import { Text } from '@codemirror/state'
+
+export const findValidPosition = (
+  doc: Text,
+  lineNumber: number, // 1-indexed
+  columnNumber: number // 0-indexed
+): number => {
+  const lines = doc.lines
+
+  if (lineNumber > lines) {
+    // end of the doc
+    return doc.length
+  }
+
+  const line = doc.line(lineNumber)
+
+  // requested line and column, or the end of the line
+  return Math.min(line.from + columnNumber, line.to)
+}