Adjust modules for compatibility with ipl-stdlib modernization

[Jan-Schuppik]

depends on:

• Add strict type declarations and modernize codebase #63
• Support PHP 8.5 ipl-html#184
• Add strict type declarations and modernize codebase ipl-orm#155
• Modernize code according to other ipl changes ipl-web#354
• Adapt to ipl-stdlib strict typing ipl-html#187
• Modernize the code icinga-notifications-web#403
• Modernize code icingaweb2-module-vspheredb#611

Several modules need to be updated to align with the recent modernization of ipl-stdlib.

• ipl-html
• ipl-orm
• ipl-web
• notifications-web
• vspheredb

ipl-html

- src/FormElement/FormElements.php
    - isValidEvent()
    - addDecoratorLoader()
    - addElementLoader()
- src/Contract/FormElement.php
    - addMessage()

ipl-orm

- src/Common/PropertiesWithDefaults.php
    - getProperty()

ipl-web

- src/Control/SearchBar.php
    - isValidEvent()

notifications-web

- ContactForm
    - isValidEvent()

vspheredb

- VCenterShipMetricsForm
    - isValidEvent()
 - PerfdataConsumerForm
   - isValidEvent()

[BastianLedererIcinga]

Icinga/ipl-orm@537a36f adds the required changes in ipl-orm.