Add persistFilter to GridModelPersistOptions

[ghsolomon]

GridModel currently supports the following GridModelPersistOptions:

    /** True (default) to include column state or provide column-specific PersistOptions. */
    persistColumns?: boolean | PersistOptions;
    /** True (default) to include grouping state or provide grouping-specific PersistOptions. */
    persistGrouping?: boolean | PersistOptions;
    /** True (default) to include sort state or provide sort-specific PersistOptions. */
    persistSort?: boolean | PersistOptions;

Add an additional persistFilter?: boolean | PersistOptions flag to support persisting a Grid's filter state. Will only be able to support persisting CompoundFilter | FieldFilter (FunctionFilter is not serializable). See FilterChooserModel, which currently supports persisting a filter value.