Revert to previous explicit soft float less operator

[heifner]

Change Description

• Reverts part of Fix upper_bound bug in chain_plugin #6285 which broke quick restart of nodeos.

The name of a chainbase index is derived from the demangled type, see: https://github.com/EOSIO/chainbase/blob/8ca96ad6b18709d65a7d1f67f8893978f25babcf/include/chainbase/chainbase.hpp#L783

• Fix upper_bound bug in chain_plugin #6285 changed the name of a couple of indexes:

==before==
typedef secondary_index<float64_t,index_double_object_type,soft_double_less>::index_object index_double_object;
typedef secondary_index<float64_t,index_double_object_type,soft_double_less>::index_index index_double_index;

typedef secondary_index<float128_t,index_long_double_object_type,soft_long_double_less>::index_object index_long_double_object;
typedef secondary_index<float128_t,index_long_double_object_type,soft_long_double_less>::index_index index_long_double_index;
==after==
typedef secondary_index<float64_t,index_double_object_type>::index_object index_double_object;
typedef secondary_index<float64_t,index_double_object_type>::index_index index_double_index;

typedef secondary_index<float128_t,index_long_double_object_type>::index_object index_long_double_object;
typedef secondary_index<float128_t,index_long_double_object_type>::index_index index_long_double_index;

• This PR reverts these changes so that the name used for the index is as it was before.

Consensus Changes

• Fix upper_bound bug in chain_plugin #6285 didn't exactly break consensus it just corrupted shared memory so that consensus was not possible without a full replay.