Fix type declarations for two functions, better checking of value

[gudmdharalds]

This pull request will fix type declarations for two functions (vipgocs_phpcs_cachedb_remove(), vipgocs_scan_files()) and perform more sanity checking of returned data from a called function (in vipgocs_scan_files()).

TODO:

• [x] Fix type declarations
• [x] Better sanity checking of data returned
• [x] Run full-unit tests
• [x] Check automated unit-tests
• [x] Manual testing

[wpcomvip-vipgoci-bot]

Scanning latest commit did not yield any new issues. Please have a look at older feedback still existing (commit-ID: e73605b197c32bb637818778cac986118335a88f)

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This bot provides automated PHP linting and PHPCS scanning. For more information about the bot and available customizations, see our documentation.

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Scan run detail

Software versions vip-go-ci version: 1.2.6 PHP runtime version for vip-go-ci: 8.1.10 PHP runtime for linting: PHP 8.1: 8.1.10 PHP runtime version for PHPCS: 7.4.30 PHPCS version: 3.7.1 PHP runtime version for SVG scanner: 7.4.30 Options file (.vipgoci_options) Options file enabled: true Configurable options: skip-execution skip-draft-prs lint-modified-files-only phpcs phpcs-severity phpcs-sniffs-include phpcs-sniffs-exclude report-no-issues-found review-comments-sort review-comments-include-severity post-generic-pr-support-comments review-comments-sort scan-details-msg-include svg-checks autoapprove autoapprove-php-nonfunctional-changes Options altered: phpcs-severityset to1 phpcs-sniffs-includeset toGeneric.PHP.DisallowShortOpenTag, Squiz.PHP.CommentedOutCode phpcs-sniffs-excludeset toWordPress.Security.EscapeOutput, WordPress.PHP.DevelopmentFunctions, WordPress.WP.AlternativeFunctions, WordPress.PHP.DiscouragedPHPFunctions, WordPress.Files.FileName, Squiz.Commenting.FileComment, Generic.PHP.Syntax skip-draft-prsset to

PHP lint options PHP lint files enabled: true Lint modified files only: true Directories not PHP linted: None SVG configuration SVG scanning enabled: true Auto-approval configuration Auto-approvals enabled: true Non-functional changes auto-approved: true Auto-approved file-types: css csv eot gif gz ico ini jpeg jpg json less map md mdown mo mp4 otf pcss pdf po pot png sass scss styl ttf txt woff woff2 yml

PHPCS configuration PHPCS scanning enabled: true PHPCS severity level: 1 Standard(s) used: PHPCompatibility PHPCompatibilityParagonieRandomCompat PHPCompatibilityParagonieSodiumCompat VariableAnalysis WordPress Runtime set: testVersion 8.1- Custom sniffs included: Generic.PHP.DisallowShortOpenTag Squiz.PHP.CommentedOutCode Custom sniffs excluded: WordPress.Security.EscapeOutput WordPress.PHP.DevelopmentFunctions WordPress.WP.AlternativeFunctions WordPress.PHP.DiscouragedPHPFunctions WordPress.Files.FileName Squiz.Commenting.FileComment Generic.PHP.Syntax Directories not PHPCS scanned: None