fix: TransactionDetail reads a transaction from the Blockscout of the network it was sent on (closes #623)

TransactionDetail read the block, network details and calldata from the
active network's Blockscout and decoded the calldata for the active network,
so after a network switch a transaction sent on the other network showed none
of them. It now reads them from the Blockscout Settings has for the network
the transaction was sent on, and decodes the calldata for that network.
reviewedNetworkEndpoints() in the shared view helpers gives that network's RPC
and Blockscout URLs, picked as reviewedNetworkProvider() picked its node;
reviewedNetworkProvider() now uses it.

Model: opus-5-5

README.md

@@ -1972,8 +1972,10 @@ view would leave a wallet one click from deletion.
 #### TransactionDetail (`transaction`)
 
 - **When**: User tapped a transaction row on Home, AddressDetail, or
-  AddressToken. Its etherscan links open the explorer of the network the
-  transaction was sent on, whichever network is active.
+  AddressToken. The screen describes the transaction on the network it was sent
+  on, whichever network is active: its block, network details, decoded details
+  and raw data are read from that network's Blockscout, the one Settings has for
+  it, and its etherscan links open that network's explorer.
 - **Elements** (grouped into logical blocks using light well containers; field
   labels are self-explanatory so groups have no headings):
     - "Transaction" heading, "Back" button