Decrease leveldb storage usage

[olehnikolaiev]

run the following test:
add 100mb data to state - leveldb storage usage grows up to 250mb
erase the data

leveldb storage usage is still ~200mb
need to investigate the reason and fix it

@oleksandrSydorenkoJ to add more details and logs

[oleksandrSydorenkoJ]

skalenetwork/schain:3.17.0-beta.5
skale_schain_polite-friendly-alphard

0x8a6B98607a18B5855009E644c666505Bf0384594
before test

"skaledDBUsage":{"blocks.db_disk_usage":101725369,"contractStorageUsed":2137664,"pieceUsageBytes":232798489,"state.db_disk_usage":82198395}}

after load of 100 MB

"skaledDBUsage":{"blocks.db_disk_usage":103025913,"contractStorageUsed":106612384,"pieceUsageBytes":233597727,"state.db_disk_usage":195984235}}}

after self-destruct of 100 MB

"skaledDBUsage":{"blocks.db_disk_usage":103129051,"contractStorageUsed":106612352,"pieceUsageBytes":233610683,"state.db_disk_usage":262751272}}}

self-destruct-doesnt-works.txt