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.

tests/unit/application/Parser/Script/Compiler/Expressions/Pipes/PipeDefinitions/EscapeDoubleQuotes.spec.ts

@@ -8,6 +8,12 @@ describe('EscapeDoubleQuotes', () => {
   const sut = new EscapeDoubleQuotes();
   // act
   runPipeTests(sut, [
+    ...getAbsentStringTestCases({ excludeNull: true, excludeUndefined: true })
+      .map((testCase) => ({
+        name: 'returns as it is when if input is missing',
+        input: testCase.absentValue,
+        expectedOutput: testCase.absentValue,
+      })),
     {
       name: 'using "',
       input: 'hello "world"',
@@ -23,10 +29,5 @@ describe('EscapeDoubleQuotes', () => {
       input: '""hello world""',
       expectedOutput: '"^"""^""hello world"^"""^""',
     },
-    ...getAbsentStringTestCases().map((testCase) => ({
-      name: 'returns as it is when if input is missing',
-      input: testCase.absentValue,
-      expectedOutput: testCase.absentValue,
-    })),
   ]);
 });

tests/unit/application/Parser/Script/Compiler/Expressions/Pipes/PipeDefinitions/InlinePowerShell.spec.ts

@@ -1,5 +1,6 @@
 import { describe } from 'vitest';
 import { InlinePowerShell } from '@/application/Parser/Script/Compiler/Expressions/Pipes/PipeDefinitions/InlinePowerShell';
+import { getAbsentStringTestCases } from '@tests/unit/shared/TestCases/AbsentTests';
 import { IPipeTestCase, runPipeTests } from './PipeTestRunner';
 
 describe('InlinePowerShell', () => {
@@ -7,11 +8,12 @@ describe('InlinePowerShell', () => {
   const sut = new InlinePowerShell();
   // act
   runPipeTests(sut, [
-    {
-      name: 'returns undefined when if input is undefined',
-      input: undefined,
-      expectedOutput: undefined,
-    },
+    ...getAbsentStringTestCases({ excludeNull: true, excludeUndefined: true })
+      .map((testCase) => ({
+        name: 'returns as it is when if input is missing',
+        input: testCase.absentValue,
+        expectedOutput: '',
+      })),
     ...prefixTests('newline', getNewLineCases()),
     ...prefixTests('comment', getCommentCases()),
     ...prefixTests('here-string', hereStringCases()),