PHP 8.0 Compatibility

[abugey]

• [x] Analyse code regarding PHP 8 compatibility
• [x] Fix deprecations found (to be specified)

internal reference: 19712

[abugey]

• no PHP 8.0 compatibility issues found
• Upgrade civix code

[jofranz]

64 might be related

[pbatroff]

I updated the Cache_Lite Library in place, so updating shouldn't be a big issue.

This needs to be tested in a productive/busy environment for release 1.0.0