Redesign transaction block

Redesign transaction block:
1. Move arrows to top of page, so all navigation between blocks would be in one place.
2. Remove current logic of searching block by clicking on block number.
3. Create input for block searching and place it like shown below
`-----------------------------------------------`
`| <- BLOCK #1234456 [__Go_to_Block__] [🔍] -> |`

No file or test is named. Start by locating the transaction-block view and tracing its existing arrow navigation and block-number lookup. Done means navigation is consolidated at the top and the old click-based lookup is replaced by the requested block-search input and controls.

Written by the indexing model from the issue text.