Currently the scoped typeahead search prototype hard-codes 'I:' 'P:' 'L:' and 'E:' prefixes for selecting a scope via the keyboard. These prefixes should be set by configuration.

Acceptance Criteria

• The keyboard shortcut / prefix for selecting scope can be configured in LocalSettings
• Absent any configuration, no prefix / shortcut is active
• If a prefix is entered from the configured prefixes for a scope that is not available (because, for example, the corresponding extension is not installed), the prefix should be ignored / treated as search input.
• The solution should also switch namespaces with their lowercase equivalent i.e. (e: for EntitySchemas, p: for Properties, l: for Lexemes, i: for Items), as this is a pattern that exists in the current search.