Rename `helpers/{view-filter => filter-annotations}`

Rename the module to match the main function it exports. This hopefully make it
more obvious what the module does.

src/sidebar/helpers/test/view-filter-test.js → src/sidebar/helpers/test/filter-annotations-test.js

-import { filterAnnotations, $imports } from '../view-filter';
+import { filterAnnotations, $imports } from '../filter-annotations';
 
 function isoDateWithAge(age) {
   return new Date(Date.now() - age * 1000).toISOString();
@@ -17,7 +17,7 @@ const poem = {
           Only this and nothing more.”`,
 };
 
-describe('sidebar/helpers/view-filter', () => {
+describe('sidebar/helpers/filter-annotations', () => {
   let fakeUnicode;
 
   beforeEach(() => {

src/sidebar/helpers/test/thread-annotations-test.js

@@ -45,7 +45,7 @@ describe('sidebar/helpers/thread-annotations', () => {
     $imports.$mock({
       './build-thread': { buildThread: fakeBuildThread },
       '../util/query-parser': fakeQueryParser,
-      './view-filter': { filterAnnotations: fakeFilterAnnotations },
+      './filter-annotations': { filterAnnotations: fakeFilterAnnotations },
     });
   });
 

src/sidebar/helpers/thread-annotations.ts

@@ -3,9 +3,9 @@ import { memoize } from '../util/memoize';
 import { parseFilterQuery } from '../util/query-parser';
 import { buildThread } from './build-thread';
 import type { Thread, BuildThreadOptions } from './build-thread';
+import { filterAnnotations } from './filter-annotations';
 import { shouldShowInTab } from './tabs';
 import { sorters } from './thread-sorters';
-import { filterAnnotations } from './view-filter';
 
 export type ThreadState = {
   annotations: Annotation[];