[Feature] Add methods to retrieve full_blocks and full_blocks_with_txs in `watch` and `subscribe` methods.

[yash-atreya]

Component

provider, pubsub

Describe the feature you would like

Motivation

Currently, the watch_blocks methods only returns block hashes and subscribe_blocks returns complete blocks but not with transaction bodies.

Solution

Add the following methods:

1. watch_full_blocks which returns complete block bodies.
2. watch_full_blocks_with_txs, which returns the block body with the tx objects in that block.
3. subscribe_blocks_with_txs which returns the block body with the tx objects in that block.

Additional context

No response