Use header size constant for faster start-ups

[quantumagi]

The code below will at times take extremely long to run:

        public void Initialize(ChainedHeader consensusTip)
        {
            ChainedHeader current = consensusTip;

            while (current.Previous != null)
            {
                current.Previous.Next.Add(current);
                this.chainedHeadersByHash.Add(current.HashBlock, current);
                this.ChainedBlocksDataBytes += current.Header.HeaderSize;

                // TODO when pruned node is implemented it should be header only for pruned blocks
                current.BlockDataAvailability = BlockDataAvailabilityState.BlockAvailable;
                current.BlockValidationState = ValidationState.FullyValidated;

                current = current.Previous;
            }

This is due to this.ChainedBlocksDataBytes += current.Header.HeaderSize;

        public BlockHeader Header
        {
            get { return this.ChainStore.GetHeader(this, this.HashBlock); }
        }

This line of code actually reads the header from the chain store database just to access the underlying constant BlockHeader.Size:

public const int Size = 80;
...
public virtual long HeaderSize => Size;

[fassadlr]

@quantumagi I noticed that the HeaderSize property is overridden for proven headers:

public override long HeaderSize => Size + this.MerkleProofSize + this.SignatureSize + this.CoinstakeSize;

As we working with ProvenHeaders in STRAX, arent we always calling into ProvenBlockHeader's vesion of header size?

[quantumagi]

As we working with ProvenHeaders in STRAX, arent we always calling into ProvenBlockHeader's vesion of header size?

It's a SmartContractPoABlockHeader which derives directly from PoABlockHeader : BlockHeader with no HeaderSize override:

Notice that there is a separate member variable for proven headers.

[fassadlr]

Remove the logging etc as well :)