Add new view keywords and new functions

[emrberk]

No description provided.

[javier]

I found

keywords: suspend (part of alter table)

functions: nanos, arg_max, arg_min, approx_count_distinct, bit_and, bit_or, bit_xor, bool_and, bool_or, current_setting, export_files(), files, geo_distance_meters, geo_within_radius_latlon, geomean, import_files, mode, parquet_scan, pg_extension, rnd_interval, rnd_symbol_weighted, rnd_symbol_zipf, to_long256, to_timestamp_ns, within_box, within_radius

constants: epoch, quarter, century, decade, millennium, dow, doy, isodow, isoyear (these are used by extract https://questdb.com/docs/query/functions/date-time/#extract)