Refactor blobstor configuration #1522
Description
Make blobstor configuration contain multiple same-level "blobstors", each with it's own policy.
blobstor:
- type: blobovnicza.tree
path: /srv/neofs/small0
size: 4g
depth: 1
width: 4
opened_cache_capacity: 50
policy:
max_object_size: 1024k
- type: fstree
path: /srv/neofs/big0
compress: true
perm: 0644
depth: 5
- Put fstree and blobovnicza tree configuration on a single level #1523
- Reuse bolt DB configuration between metabase, writecache, blobovnicza #1524
- Add a policy for filtering objects by type #1525
- Add single bolt DB storage type (used in writecache, could be used for auxilliary objects) #1526
- Write a sanity check (every object should be places in at least one storage type) or disallow specifying a policy for the last type of storage or mark some as default. #1527
- Make writecache configuration similar to the blobstor one (however, last storage can have some policy, some objects are not stored in writecache). #1528