Important: #70849 - Make search levels in live search and list search consistent

See forge#70849

Description

In order to make the searchlevel handling consistent between live and list search a new PageTS option has been added.

mod.web_list.searchLevel.items {
        -1 = EXT:lang/Resources/Private/Language/locallang_core.xlf:labels.searchLevel.infinite
        0 = EXT:lang/Resources/Private/Language/locallang_core.xlf:labels.searchLevel.0
        1 = EXT:lang/Resources/Private/Language/locallang_core.xlf:labels.searchLevel.1
        2 = EXT:lang/Resources/Private/Language/locallang_core.xlf:labels.searchLevel.2
        3 = EXT:lang/Resources/Private/Language/locallang_core.xlf:labels.searchLevel.3
        4 = EXT:lang/Resources/Private/Language/locallang_core.xlf:labels.searchLevel.4
}

This makes it possible to add custom search level entries.