accounts: fix infinite scroll over-loading, use scrollend+polyfill

calculation for number of rows to be drawn was wrong, fixed now. To
compensate for overshooting with fast scrolling, speed is calculated
using previous scrollY in rows/scroll, and used to render more rows.
Also, the "scrollend" event is used to load more at the end of a scroll
always. Since this isn't available on safari/webkit(2gtk), a polyfill
has been added.

package-lock.json

@@ -9,6 +9,7 @@
       "version": "1.0.0",
       "license": "ISC",
       "dependencies": {
+        "@af-utils/scrollend-polyfill": "^0.0.14",
         "@ts-stack/markdown": "^1.4.0",
         "@types/node": "^20.3.0",
         "a17t": "^0.10.1",
@@ -36,6 +37,12 @@
         "esbuild": "^0.18.20"
       }
     },
+    "node_modules/@af-utils/scrollend-polyfill": {
+      "version": "0.0.14",
+      "resolved": "https://registry.npmjs.org/@af-utils/scrollend-polyfill/-/scrollend-polyfill-0.0.14.tgz",
+      "integrity": "sha512-pThXK3XqbWeJHJJAEzhNqCEgOiZ7Flk/Wj/uM6+TGJuA/3n/NeKP3C+5o4jt79i46Cc18iA0kJaMd056GQTfYQ==",
+      "license": "MIT"
+    },
     "node_modules/@alloc/quick-lru": {
       "version": "5.2.0",
       "resolved": "https://registry.npmjs.org/@alloc/quick-lru/-/quick-lru-5.2.0.tgz",
@@ -7293,6 +7300,11 @@
     }
   },
   "dependencies": {
+    "@af-utils/scrollend-polyfill": {
+      "version": "0.0.14",
+      "resolved": "https://registry.npmjs.org/@af-utils/scrollend-polyfill/-/scrollend-polyfill-0.0.14.tgz",
+      "integrity": "sha512-pThXK3XqbWeJHJJAEzhNqCEgOiZ7Flk/Wj/uM6+TGJuA/3n/NeKP3C+5o4jt79i46Cc18iA0kJaMd056GQTfYQ=="
+    },
     "@alloc/quick-lru": {
       "version": "5.2.0",
       "resolved": "https://registry.npmjs.org/@alloc/quick-lru/-/quick-lru-5.2.0.tgz",