Fix unserialize() warning flood with PHP 8.3+. Fix deprecated warnings.

[colinfoster]

As of PHP 8.3 unserialize() triggers E_WARNING instead of E_NOTICE causing SRDB to dump thousands of notices (one for every string checked) to the screen as it tries to unserialize non-serialized strings. It now checks for serialized data before trying to unserialize.

Fixed Deprecation warning creating dynamic property: alter_collation.

Fixed Deprecation warning when passing null to htmlentities().

[mikecollet]

Yesterday I was using SRDB V4.1.3 running on the latest PHP version and encountered this problem. I have tested @colinfoster solution and it works perfectly!

[Slamik]

Tested on PHP 8.3 - everything works well!

[BackuPs]

Tested in wp 8.3.4 Works just fine !

[windhamdavid]

8.3.9 works fine. Noticed the merge and review went unanswered here so people wanting these changes ( thanks to @colinfoster via #385 ) should grab the updates over @ https://github.com/colinfoster/Search-Replace-DB/

[midweste]

This fatal errors if you use composer and include "interconnectit/search-replace-db" with wordpress.

I dont think its a good idea to be declaring is_serialized in global scope. Pull request to make class method and not pollute the global namespace here #397

Fatal error: Cannot redeclare is_serialized() (previously declared in /app/vendor/interconnectit/search-replace-db/srdb.class.php:1386) in /app/web/wp-includes/functions.php on line 669

Fatal error: Uncaught Error: Call to undefined function wp_die() in /app/web/wp-includes/class-wp-fatal-error-handler.php:245
Stack trace:
#0 /app/web/wp-includes/class-wp-fatal-error-handler.php(156): WP_Fatal_Error_Handler->display_default_error_template(Array, false)
#1 /app/web/wp-includes/class-wp-fatal-error-handler.php(60): WP_Fatal_Error_Handler->display_error_template(Array, false)
#2 [internal function]: WP_Fatal_Error_Handler->handle()
#3 {main}
thrown in /app/web/wp-includes/class-wp-fatal-error-handler.php on line 245