misc stuff to avoid scan loop (#1389)

* Implemented a workaround for nginx users with BlockCommonExploits enabled, which would interfere with book image escaping done by Kavita when images had ../ in their path.

* Added back to top support on all pages but those that untilize virtual scrolling without a parent scroll.

* Hide jumpbar on pages where there is no scroll

* Refactored jumbar code into a dedicated service

* Stash some jumpkey resume code as I can't get it working with the virtual scroller.

* Don't allow non-admins to see File locations on card detail drawer.

* Some cleanup on GetServerInfo

* When an error occurs in register, delete the user on exception.

* Fixed a NPE in Stat collection for brand new users

* When we catch an exception on registering a new user, delete the user as rolling back doesn't do anything.

* Don't close typeahead when we are selecting options from it

* Added shortcut key H to open shortcut modal on manga reader

* When processing progress updates on cards, for volumes, properly find the chapter to update pages read.

* Hide cover image on reading list if it's not set and fixed a missing closing div tag

* Hide collection poster when nothing is set on collection detail

* Small fix around updating state

* Sped up the bookmark image call by removing one DB call

* Fixed broken test from change in bookmark code

* Fixed an oversight where if there is no tag in ComicInfo after a chapter was updated with People or Genres, then the People/Genres would never be removed.

* Added test with TagHelper

* Fixed a bug where 2 clear buttons would show on search bar due to browser injecting their own. Search bar wont show clear button until text is typed.

* Fixed a bug where InstallID wasn't being selected correctly in converter

UI/Web/src/app/_services/jumpbar.service.ts

@@ -0,0 +1,83 @@
+import { Injectable } from '@angular/core';
+import { JumpKey } from '../_models/jumpbar/jump-key';
+
+const keySize = 25; // Height of the JumpBar button
+
+@Injectable({
+  providedIn: 'root'
+})
+export class JumpbarService {
+
+  resumeKeys: {[key: string]: string} = {};
+
+  constructor() { }
+
+
+  getResumeKey(key: string) {
+    if (this.resumeKeys.hasOwnProperty(key)) return this.resumeKeys[key];
+    return '';
+  }
+
+  saveResumeKey(key: string, value: string) {
+    this.resumeKeys[key] = value;
+  }
+
+  generateJumpBar(jumpBarKeys: Array<JumpKey>, currentSize: number) {
+    const fullSize = (jumpBarKeys.length * keySize);
+    if (currentSize >= fullSize) {
+      return [...jumpBarKeys];
+    }
+
+    const jumpBarKeysToRender: Array<JumpKey> = [];
+    const targetNumberOfKeys = parseInt(Math.floor(currentSize / keySize) + '', 10);
+    const removeCount = jumpBarKeys.length - targetNumberOfKeys - 3;
+    if (removeCount <= 0) return jumpBarKeysToRender;
+
+    const removalTimes = Math.ceil(removeCount / 2);
+    const midPoint = Math.floor(jumpBarKeys.length / 2);
+    jumpBarKeysToRender.push(jumpBarKeys[0]);
+    this.removeFirstPartOfJumpBar(midPoint, removalTimes, jumpBarKeys, jumpBarKeysToRender);
+    jumpBarKeysToRender.push(jumpBarKeys[midPoint]);
+    this.removeSecondPartOfJumpBar(midPoint, removalTimes, jumpBarKeys, jumpBarKeysToRender);
+    jumpBarKeysToRender.push(jumpBarKeys[jumpBarKeys.length - 1]);
+
+    return jumpBarKeysToRender;
+  }
+
+  removeSecondPartOfJumpBar(midPoint: number, numberOfRemovals: number = 1, jumpBarKeys: Array<JumpKey>, jumpBarKeysToRender: Array<JumpKey>) {
+    const removedIndexes: Array<number> = [];
+    for(let removal = 0; removal < numberOfRemovals; removal++) {
+      let min = 100000000;
+      let minIndex = -1;
+      for(let i = midPoint + 1; i < jumpBarKeys.length - 2; i++) {
+        if (jumpBarKeys[i].size < min && !removedIndexes.includes(i)) {
+          min = jumpBarKeys[i].size;
+          minIndex = i;
+        }
+      }
+      removedIndexes.push(minIndex);
+    }
+    for(let i = midPoint + 1; i < jumpBarKeys.length - 2; i++) {
+      if (!removedIndexes.includes(i)) jumpBarKeysToRender.push(jumpBarKeys[i]);
+    }
+  }
+
+  removeFirstPartOfJumpBar(midPoint: number, numberOfRemovals: number = 1, jumpBarKeys: Array<JumpKey>, jumpBarKeysToRender: Array<JumpKey>) {
+    const removedIndexes: Array<number> = [];
+    for(let removal = 0; removal < numberOfRemovals; removal++) {
+      let min = 100000000;
+      let minIndex = -1;
+      for(let i = 1; i < midPoint; i++) {
+        if (jumpBarKeys[i].size < min && !removedIndexes.includes(i)) {
+          min = jumpBarKeys[i].size;
+          minIndex = i;
+        }
+      }
+      removedIndexes.push(minIndex);
+    }
+
+    for(let i = 1; i < midPoint; i++) {
+      if (!removedIndexes.includes(i)) jumpBarKeysToRender.push(jumpBarKeys[i]);
+    }
+  }
+}