SECFIND-244: Set block_index when attaching created canister

[dskloetd]

Motivation

We want to store the block index of the funding transaction for created canisters.
See this doc for details.

Changes

1. Add block_index to canister details in frontend candid.
2. Add blockIndex in canister API.
3. Specify blockIndex from the transaction when attaching a created canister.

Tests

1. Unit tests updated.
2. Tested manually in a branch with more end-to-end changes.

Todos

• Add entry to changelog (if necessary).
  not yet

[yhabib]

Thanks