Import/Export Blockchain

[noobvie]

Is your feature request related to a problem? Please describe.
Yesterday, when trying to run a node in a small computer on Ubuntu, somehow the node was stuck after synchronized header parts (tip hash, tip timestamp) and it could not continue to synchronize for chain parts after several hours.
I checked the node log and nothing unusual found.

*Describe the solution I did
I had an idea to work around with this situation by zipping the chain data in another running node in directory ~/.grin/main/chain_data, then unzip it in same directory in the node which had issue. I re-executed grin node again and both header and chain data are synced well with exact information like other nodes.

Describe alternatives I suggest
I did some research and found Monero has a feature like this with commands to import/export raw blockchain (https://github.com/monero-project/monero/tree/master/src/blockchain_utilities) . I see it useful for low end node which has limited hardware resource and bandwidth and it would shorten the time to sync.
I'm not sure if it will impact on security viewpoint in Mimblewimble protocol but I think it's good to raise the idea anyway.