Fix LocalDateTime bug

[pinheirosam]

1. Issue Link:
#29

2. Brief explanation of a change:
Removing LocalDateTime from the parser as it converts to a Date format that will not work with SQL or JPA expressions

3. Will it break existing clients and code in production?
No.

[m-laff]

I have a similar situation:

1. a graphql field endDate: DateTime
2. a filter I would like to add as an input:

input BookFilter {
    endDate: DateTimeExpression
}
input input DateTimeExpression {
    between: [DateTime!]
}

3. a database field end_date datetime null,
4. the Java object has a field

    @Column(name = "end_date")
    private LocalDateTime endDate;

The query filter translation current changes the input DateTime to a format which SQL (MySQL) cannot use.