Update logging and remove stat

[DenisCarriere]

• [x] remove stat TABLE
• [x] prevent outgoing EOS transfers when FLAG_ENABLE_RAM_TRANSFER_ON_CLAIM=true
• [x] remove sell_ram param
• [x] prevent contract (self) from drops::generate be recipient of drops::transfer
• [x] add modify_ram_bytes helper method
• [x] replace logbalances & logstat with new logging actions logrambytes & logdrops
  • add before_ram_bytes & before_drops to logs

    
    // @logging
    [[eosio::action]]
    void logrambytes(const name owner, const int64_t before_ram_bytes, const int64_t ram_bytes);

// @logging [[eosio::action]] void logdrops(const name owner, const int64_t before_drops, const int64_t drops);