chore: remove dead exports and share copied view helpers (closes #168)

AddressDetail and AddressToken defined their own isoDate() and
timeAgo(), hiding the shared pair in helpers.js, so a fix there would
not have reached them. The copies were identical and are deleted;
blockieHtml() and tokenLabel(), each defined twice, move to helpers.js.
A new test shows the history rows and the transaction detail view
write the time with the shared pair.

Deleted as never called: explorerLink(), ETHEREUM_SEPOLIA_CHAIN_ID,
getWalletValue() and getTotalValue() with their tests. Home's "Total:"
is the active address's total, as README.md already says.
addressColor() and etherscanAddressUrl() are no longer exported.

Model: opus-5-5

src/popup/views/transactionDetail.js

@@ -13,6 +13,7 @@ const {
     isoDate,
     timeAgo,
     renderAddressHtml,
+    blockieHtml,
     attachCopyHandlers,
     copyableHtml,
     etherscanLinkHtml,
@@ -23,7 +24,6 @@ const {
 const { state } = require("../../shared/state");
 const { nativeCurrencyByChainId } = require("../../shared/networks");
 const { formatEther, formatUnits } = require("ethers");
-const makeBlockie = require("ethereum-blockies-base64");
 const { log, debugFetch } = require("../../shared/log");
 const { decodeCalldata } = require("./approval");
 
@@ -48,11 +48,6 @@ function getTransactionType(tx) {
     return "Native " + nativeCurrencyByChainId(tx.chainId) + " Transfer";
 }
 
-function blockieHtml(address) {
-    const src = makeBlockie(address);
-    return `<img src="${escapeHtml(src)}" width="48" height="48" style="image-rendering:pixelated;border-radius:50%;display:inline-block">`;
-}
-
 function txAddressHtml(address, ensName, title) {
     const blockie = blockieHtml(address);
     return (