Fix/receipt migration not working with compact receipt

[asdacap]

• Fix receipt migration detection not working. Can detect if encoding is not the right one and initiate receipt migration.
• Remove tx index if needed according to config.
• Run receipt migration with multiple thread, took roughly the same amount of time as old receipts sync. Add config to limit concurrency.
• Compact DB after receipt migration to actually reduce receipt size.
• Add a flag to force start receipt migration.

Types of changes

What types of changes does your code introduce?

• Bugfix (a non-breaking change that fixes an issue)
• New feature (a non-breaking change that adds functionality)

Testing

Requires testing

• Yes
• No

If yes, did you write tests?

• Yes
• No

Notes on testing

• Confirm can change config from compact receipt and full receipt and the other way arount.
• Confirm if receipt is already according to config, it wont start receipt migration.
• Confirm disk space goes down when moving from full receipt to compact receipt.

[LukaszRozmej]

Not all db's have Keccaks as keys?

[asdacap]

Thats true yes. But I figure the range of keccak should overlap most keys.