Refactor to enforce strictNullChecks

This commit applies `strictNullChecks` to the entire codebase to improve
maintainability and type safety. Key changes include:

- Remove some explicit null-checks where unnecessary.
- Add necessary null-checks.
- Refactor static factory functions for a more functional approach.
- Improve some test names and contexts for better debugging.
- Add unit tests for any additional logic introduced.
- Refactor `createPositionFromRegexFullMatch` to its own function as the
  logic is reused.
- Prefer `find` prefix on functions that may return `undefined` and
  `get` prefix for those that always return a value.

src/presentation/components/Scripts/View/Tree/TreeViewAdapter/TreeNodeMetadataConverter.ts

@@ -5,7 +5,6 @@ import { TreeInputNodeData } from '../TreeView/Bindings/TreeInputNodeData';
 export function getNodeMetadata(
   treeNode: ReadOnlyTreeNode,
 ): NodeMetadata {
-  if (!treeNode) { throw new Error('missing tree node'); }
   const data = treeNode.metadata as NodeMetadata;
   if (!data) {
     throw new Error('Provided node does not contain the expected metadata.');
@@ -14,7 +13,6 @@ export function getNodeMetadata(
 }
 
 export function convertToNodeInput(metadata: NodeMetadata): TreeInputNodeData {
-  if (!metadata) { throw new Error('missing metadata'); }
   return {
     id: metadata.id,
     children: convertChildren(metadata.children, convertToNodeInput),
@@ -23,7 +21,7 @@ export function convertToNodeInput(metadata: NodeMetadata): TreeInputNodeData {
 }
 
 function convertChildren<TOldNode, TNewNode>(
-  oldChildren: readonly TOldNode[],
+  oldChildren: readonly TOldNode[] | undefined,
   callback: (value: TOldNode) => TNewNode,
 ): TNewNode[] {
   if (!oldChildren || oldChildren.length === 0) {