fix: make:cell using class as view file

[paulbalandan]

Description
Fixes #7469

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[kenjis]

@paulbalandan The test fails on macOS.

$ vendor/bin/phpunit tests/system/Commands/CellGeneratorTest.php
PHPUnit 9.6.7 by Sebastian Bergmann and contributors.

Runtime:       PHP 8.1.18
Configuration: /Users/kenji/work/codeigniter/official/CodeIgniter4/phpunit.xml

.F                                                                                                                                         2 / 2 (100%)

Time: 00:00.095, Memory: 16.00 MB

There was 1 failure:

1) CodeIgniter\Commands\CellGeneratorTest::testGenerateCellSimpleName
Failed asserting that 'File created: APPPATH/Cells/Another.php\n
\n
File exists: "APPPATH/Cells/another.php"\n
\n
' contains "File created: APPPATH/Cells/another.php".

/Users/kenji/work/codeigniter/official/CodeIgniter4/tests/system/Commands/CellGeneratorTest.php:78

FAILURES!
Tests: 2, Assertions: 10, Failures: 1.