Cleaned up #included files in the .h files in the src/include
directories.

Additionally, deleted 1 unnecessary header file.

    modified:   src/include/catalog/ag_catalog.h
    modified:   src/include/catalog/ag_graph.h
    modified:   src/include/catalog/ag_label.h
    modified:   src/include/catalog/ag_namespace.h
    modified:   src/include/commands/graph_commands.h
    modified:   src/include/commands/label_commands.h
    modified:   src/include/executor/cypher_executor.h
    modified:   src/include/executor/cypher_utils.h
    modified:   src/include/nodes/ag_nodes.h
    modified:   src/include/nodes/cypher_copyfuncs.h
    modified:   src/include/nodes/cypher_nodes.h
    modified:   src/include/nodes/cypher_outfuncs.h
    modified:   src/include/nodes/cypher_readfuncs.h
    modified:   src/include/optimizer/cypher_createplan.h
    modified:   src/include/optimizer/cypher_pathnode.h
    modified:   src/include/parser/cypher_clause.h
    modified:   src/include/parser/cypher_expr.h
    modified:   src/include/parser/cypher_gram.h
    modified:   src/include/parser/cypher_item.h
    modified:   src/include/parser/cypher_parse_node.h
    modified:   src/include/parser/cypher_parser.h
    modified:   src/include/parser/cypher_transform_entity.h
    modified:   src/include/utils/ag_cache.h
    modified:   src/include/utils/ag_float8_supp.h
    modified:   src/include/utils/ag_func.h
    modified:   src/include/utils/age_global_graph.h
    modified:   src/include/utils/agtype.h
    modified:   src/include/utils/agtype_parser.h
    modified:   src/include/utils/agtype_raw.h
    modified:   src/include/utils/graphid.h
    modified:   src/include/utils/load/ag_load_edges.h
    modified:   src/include/utils/load/ag_load_labels.h
    modified:   src/include/utils/load/age_load.h

    deleted:    src/include/utils/ag_load.h