Before:
cqlsh> insert into ks.list_types (id, val) values (1, [3,4,5]);
cqlsh> select max(val) from ks.list_types;
system.max(val)
------------------------------------------------------------
0x00000003000000040000000300000004000000040000000400000005
After:
cqlsh> select max(val) from ks.list_types;
system.max(val)
--------------------
[3, 4, 5]
This is accomplished similarly to `tojson()`/`fromjson()`: functions
are generated on demand from within `cql3::functions::get()`.
Because collections can have a variety of types, including UDTs
and tuples, it would be impossible to statically define max(T t)->T
for every T. Until now, max(blob)->blob overload was used.
Because `impl_max/min_function_for` is templated with the
input/output type, which can be defined in runtime, we need type-erased
("dynamic") versions of these functors. They work identically, i.e.
they compare byte representations of lhs and rhs with
`bytes::operator<`.
Resolves#5139
9efad36fb8