**Use case**

Viewing binary data such as bitmasks, hashes, internal representation of IEEE-754 numbers, etc.
Mostly for debugging.

**Describe the solution you'd like**

Similar to `hex`/`unhex`.

`bin` - returns a string with `0` and `1`. Bits are in "human" order, most significant first. Most significant zero bits are not printed (except the case with single zero).

**Describe alternatives you've considered**

Now I have to run interactive `python` from command line, but I will be more happy using ClickHouse.

**Caveats**

The name `bin` may suggest that the function will "split data into bins" but it is completely unrelated.
#include <Functions/FunctionFactory.h>
#include <Functions/FunctionsCoding.h>
namespace DB
{
struct NameFunctionIPv4NumToString { static constexpr auto name = "IPv4NumToString"; };
struct NameFunctionIPv4NumToStringClassC { static constexpr auto name = "IPv4NumToStringClassC"; };
void registerFunctionsCoding(FunctionFactory & factory)
{
    factory.registerFunction<FunctionToStringCutToZero>();
    factory.registerFunction<FunctionCutIPv6>();
    factory.registerFunction<FunctionIPv4ToIPv6>();
    factory.registerFunction<FunctionMACNumToString>();
    factory.registerFunction<FunctionMACStringTo<ParseMACImpl>>();