refactor(tools,client): remove head and tail logic (#66524)

client/utils/__fixtures__/challenges.ts

@@ -5,12 +5,10 @@ export const challengeFiles: ChallengeFile[] = [
     contents: 'some ts',
     error: null,
     ext: 'ts',
-    head: '',
     history: ['index.ts'],
     fileKey: 'indexts',
     name: 'index',
     seed: 'some ts',
-    tail: '',
     editableRegionBoundaries: [],
     usesMultifileEditor: true,
     path: 'index.ts'
@@ -19,12 +17,10 @@ export const challengeFiles: ChallengeFile[] = [
     contents: 'some css',
     error: null,
     ext: 'css',
-    head: '',
     history: ['styles.css'],
     fileKey: 'stylescss',
     name: 'styles',
     seed: 'some css',
-    tail: '',
     editableRegionBoundaries: [],
     usesMultifileEditor: true,
     path: 'styles.css'
@@ -33,12 +29,10 @@ export const challengeFiles: ChallengeFile[] = [
     contents: 'some html',
     error: null,
     ext: 'html',
-    head: '',
     history: ['index.html'],
     fileKey: 'indexhtml',
     name: 'index',
     seed: 'some html',
-    tail: '',
     editableRegionBoundaries: [],
     usesMultifileEditor: true,
     path: 'index.html'
@@ -47,12 +41,10 @@ export const challengeFiles: ChallengeFile[] = [
     contents: 'some js',
     error: null,
     ext: 'js',
-    head: '',
     history: ['script.js'],
     fileKey: 'scriptjs',
     name: 'script',
     seed: 'some js',
-    tail: '',
     editableRegionBoundaries: [],
     usesMultifileEditor: true,
     path: 'script.js'
@@ -61,12 +53,10 @@ export const challengeFiles: ChallengeFile[] = [
     contents: 'some jsx',
     error: null,
     ext: 'jsx',
-    head: '',
     history: ['index.jsx'],
     fileKey: 'indexjsx',
     name: 'index',
     seed: 'some jsx',
-    tail: '',
     editableRegionBoundaries: [],
     usesMultifileEditor: true,
     path: 'index.jsx'
@@ -75,12 +65,10 @@ export const challengeFiles: ChallengeFile[] = [
     contents: 'some tsx',
     error: null,
     ext: 'tsx',
-    head: '',
     history: ['index.tsx'],
     fileKey: 'indextsx',
     name: 'index',
     seed: 'some tsx',
-    tail: '',
     editableRegionBoundaries: [],
     usesMultifileEditor: true,
     path: 'index.tsx'
@@ -89,12 +77,10 @@ export const challengeFiles: ChallengeFile[] = [
     contents: '{\n  "compilerOptions": {}\n}',
     error: null,
     ext: 'json',
-    head: '',
     history: ['tsconfig.json'],
     fileKey: 'tsconfigjson',
     name: 'tsconfig',
     seed: '{\n  "compilerOptions": {}\n}',
-    tail: '',
     editableRegionBoundaries: [],
     usesMultifileEditor: true,
     path: 'tsconfig.json'