Indexer: decide when to reindex

[alexcos20]

As soon as we merge #525 and derivates(526-528), we will change the structure of the DDO.
But existing nodes will not reindex old assets, only new ones, leading to inconsistency .

So, node must know when to reindex, based on version.

Proposal:

• use node version(take it from package.lock) to decide if action is needed
• hardcode a "min_version" in the code. At startup, if db.version is null, or lower that "min_version", then reset all chains and store current version (take it from package.lock)