feat(lexicon): events onSet() and initialize()

[ArtificialOwl]

adding events when working on config keys

• add onSet() which is executed when a new value is set for this config key. Can be used to modify the new value before being stored into database, or to cancel the process if the new value is considered invalid (by returning false):

(new ConfigLexiconEntry('email', ValueType::STRING, '', 'email'))->onSet(
				function (string &$value): void {
					$value = strtolower($value);
				}
			),

(new ConfigLexiconEntry('email', ValueType::STRING, '', 'email'))->onSet(
				function (string &$value): bool {
					return ((int)$value > 100);
				}
			),

• add initialize() which is executed when reading a config key that has no known value. Can be used to fill the value at first read, unless the closure returns false

not in this PR anymore

``` (new ConfigLexiconEntry('email', ValueType::STRING, '', 'email'))->initialize( function (string &$value): void { $value = $this->secureRandom->generate(5, 'abcdefghijklmnopqrstuvwxyz0123456789'); } ), ```

initialize() has been removed, will be prep in a separated PR and forgotten until it needs to be added in the future!

[come-nc]

I’m a bit reluctant because this looks like a 4th event system 😒

But it’s not really events I suppose, it’s more validators and setters… unsure.

[ArtificialOwl]

I’m a bit reluctant because this looks like a 4th event system 😒

But it’s not really events I suppose, it’s more validators and setters… unsure.

still better than having a particular condition within the general/official setter

[ArtificialOwl]

• removed initialized()