Enhancement: Add CLI options to check specific files and directories

Currently, the wp plugin check command supports excluding files and directories via --exclude-files and --exclude-directories, but there's no way to check only specific files or directories. This feature would add --include-files and --include-directories options that restrict checks to only the specified files and/or directories, working as the inverse of the exclude options.

Examples:

wp plugin check my-plugin --include-files=src/Plugin.php,src/admin/Settings.php
wp plugin check my-plugin --include-directories=src/admin,src/database
wp plugin check my-plugin --include-files=src/Plugin.php --include-directories=src/admin

If both include and exclude options are provided for the same type (e.g. --include-files and --exclude-files), the command could error as they are mutually exclusive. The --include-files and --include-directories options can be used together. Directory inclusion should work recursively, including all files within the specified directories and their subdirectories.

Start at the wp plugin check command and trace how the existing --exclude-files and --exclude-directories options select paths. Implement matching include options with recursive directory behavior, define handling for conflicting include and exclude options, and verify that the example commands restrict checks to the requested paths.