Added progress bar to file downloads

Added two new API calls, to update the server to a particular version and to get the updater status

You can now update through the UI, and a status dialog displays after

src/app/dialogs/update-progress-dialog/update-progress-dialog.component.ts

@@ -0,0 +1,44 @@
+import { Component, OnInit } from '@angular/core';
+import { PostsService } from 'app/posts.services';
+import { MatSnackBar } from '@angular/material/snack-bar';
+
+@Component({
+  selector: 'app-update-progress-dialog',
+  templateUrl: './update-progress-dialog.component.html',
+  styleUrls: ['./update-progress-dialog.component.scss']
+})
+export class UpdateProgressDialogComponent implements OnInit {
+
+  updateStatus = null;
+  updateInterval = 250;
+  errored = false;
+
+  constructor(private postsService: PostsService, private snackBar: MatSnackBar) { }
+
+  ngOnInit(): void {
+    this.getUpdateProgress();
+    setInterval(() => {
+      this.getUpdateProgress();
+    }, 250);
+  }
+
+  getUpdateProgress() {
+    this.postsService.getUpdaterStatus().subscribe(res => {
+      this.updateStatus = res;
+      if (!this.updateStatus) {
+        // update complete?
+        console.log('Update complete? or not started');
+      }
+      if (this.updateStatus && this.updateStatus['error']) {
+        this.openSnackBar('Update failed. Check logs for more details.');
+      }
+    });
+  }
+
+  public openSnackBar(message: string, action: string = '') {
+    this.snackBar.open(message, action, {
+      duration: 2000,
+    });
+  }
+
+}