fix(gui): Strictly enforce UI types with Typescript (#678)

* fix(gui): we were not checking for null everywhere

* add more null checks, enable tsconfig strict

* remove dead code

* more nullish checks

* remove unused JSONViewTree.tsx

* fix a bunch of small typescript lints

* add explanations as to why LabeledMoneroAddress.address is non-nullish but we pass in null due to typeshare limitation

* remove @mui/lab from yarn.lock

* re-add SortableQuoteWithAddress

* add guard function for ExportBitcoinWalletResponseExt ("wallet_descriptor")

* fix remaining linter errors

* remove duplicate XMR

* fix hasUnusualAmountOfTimePassed in SwapStatusAlert.tsx

src-gui/src/renderer/components/pages/help/SettingsBox.tsx

@@ -432,7 +432,7 @@ function MoneroNodeUrlSetting() {
         <Box sx={{ display: "flex", alignItems: "center", gap: 1 }}>
           <ValidatedTextField
             value={moneroNodeUrl}
-            onValidatedChange={handleNodeUrlChange}
+            onValidatedChange={(value) => value && handleNodeUrlChange(value)}
             placeholder={PLACEHOLDER_MONERO_NODE_URL}
             disabled={useMoneroRpcPool}
             fullWidth
@@ -675,7 +675,7 @@ function NodeTable({
               <ValidatedTextField
                 label="Add a new node"
                 value={newNode}
-                onValidatedChange={setNewNode}
+                onValidatedChange={(value) => setNewNode(value ?? "")}
                 placeholder={placeholder}
                 fullWidth
                 isValid={isValid}
@@ -843,7 +843,9 @@ function RendezvousPointsSetting() {
                         <ValidatedTextField
                           label="Add new rendezvous point"
                           value={newPoint}
-                          onValidatedChange={setNewPoint}
+                          onValidatedChange={(value) =>
+                            setNewPoint(value ?? "")
+                          }
                           placeholder="/dns4/rendezvous.observer/tcp/8888/p2p/12D3KooWMjceGXrYuGuDMGrfmJxALnSDbK4km6s1i1sJEgDTgGQa"
                           fullWidth
                           isValid={isValidMultiAddressWithPeerId}