Use `DeserializationContext.handleWeirdXxxValue()` for datetime deserializers

[remal]

Lets look on LocalDateTimeDeserializer (for example):

public LocalDateTime deserialize(JsonParser parser, DeserializationContext context) throws IOException {
    if (parser.hasTokenId(JsonTokenId.ID_STRING)) {
        String string = parser.getText().trim();
        // ...
        try {
            // ...
            return LocalDateTime.parse(string, _formatter);
        } catch (DateTimeException e) {
            _rethrowDateTimeException(parser, context, e, string);
        }
    }
    // ...
}

Please change it to:

public LocalDateTime deserialize(JsonParser parser, DeserializationContext context) throws IOException {
    if (parser.hasTokenId(JsonTokenId.ID_STRING)) {
        String string = parser.getText().trim();
        // ...
        try {
            // ...
            return LocalDateTime.parse(string, _formatter);
        } catch (DateTimeException e) {
            try {
                return context.handleWeirdStringValue(LocalDateTime.class, string, e.getMessage());
            } catch (Throwable t) {
                t.initCause(e);
            }
        }
    }
    // ...
}

Why do I need this? I want to create a module that defines some DeserializationProblemHandlers that allow to deserialize datetime types using several formats. Now I need to create mix-ins to override datetime deserializers.

Please apply this change to all deserializers and key deserializers.

[cowtowncoder]

Makes sense. I'll add notes to PR itself.