Refactor the search placeholder and update the collections description

Update the search placeholder to be more general, from 'Search Nodes' to 'Search', in the extra sidebar component, and update the collection description from 'Download or upload your complete project collection' to 'Download or upload your collection' in the main page.

src/frontend/src/pages/FlowPage/components/extraSidebarComponent/index.tsx

@@ -124,7 +124,7 @@ export default function ExtraSidebar() {
           type="text"
           name="search"
           id="search"
-          placeholder="Search Nodes"
+          placeholder="Search"
           className={
             INPUT_STYLE +
             "w-full border-1 dark:border-slate-600 dark:border-0.5 dark:ring-0 focus-visible:dark:ring-0 focus-visible:dark:ring-offset-1 rounded-md border border-input bg-transparent px-3 py-2 text-sm ring-offset-background file:border-0 file:bg-transparent file:text-sm file:font-medium placeholder:text-muted-foreground disabled:cursor-not-allowed disabled:opacity-50"

src/frontend/src/pages/MainPage/index.tsx

@@ -16,7 +16,7 @@ export default function HomePage() {
       <div className="w-full flex justify-between py-12 pb-2 px-6">
         <span className="text-2xl flex items-center justify-center gap-2 font-semibold">
           <Home className="w-6" />
-          My Projects
+          My Collection
         </span>
         <div className="flex gap-2">
           <Button
@@ -51,8 +51,7 @@ export default function HomePage() {
         </div>
       </div>
       <span className="flex pb-14 px-6 text-muted-foreground w-[60%]">
-        Manage your personal projects. Download or upload your complete project
-        collection.
+        Manage your personal projects. Download or upload your collection.
       </span>
       <div className="w-full p-4 grid gap-4 md:grid-cols-2 lg:grid-cols-4">
         {flows.map((flow, idx) => (