Feature/avail sync

[Yiakman]

Implements

• AvailClient with the calls to the node and light-client for block and data fetching
• fetcher for blocks and processing data
• App deployment: Now it starts avail node, then a deploy script registers a new appId and then it launches the light-client with that same appId so it runs on app-mode
• Updated types and primitives

Fetching data works first by checking on the block header app_lookup.index if the appId appears listed. Data is decoded from base64 in the fetcher and passed as a result.