Add Help button to Get from Internet dialog

[papeh]

Part of https://jira.sil.org/browse/LT-21209

This change is 

[github-actions[bot]]

Test Results

       6 files   -        4     321 suites   - 122   57m 35s :stopwatch: - 29m 19s    956 tests  -      17     897 :heavy_check_mark:  -      21    59 :zzz: +  4  0 :x: ±0  3 090 runs   - 1 100  2 942 :heavy_check_mark:  - 1 045  148 :zzz:  - 55  0 :x: ±0 

Results for commit af92d5cb. ± Comparison against base commit 12ec3296.

This pull request removes 17 tests.

``` After2Syncs_HistoryHas2 After2Syncs_WithFilter_OnlyFilteredItemsShown AsyncLocalCheckIn_GivesGoodResult AsyncLocalCheckIn_NoHgLockWarningWithMultipleWorkers AsyncLocalCheckIn_NoPreviousRepoCreation_Throws BeforeAnySyncing_EmptyHistory CanMakeNotesBarWithOtherFiles CanShowNotesBar CreateNotesBar GetRepositoriesToList_NoRepositoriesKnown_GivesUsb … ```

This pull request skips 4 tests.

``` CanShowNotesBrowserPage CreateNotesBrowser GetNotesBarAndBrowser_MakeNewAnnotationWithBar_BrowserSeesIt Main_Utf8FilePaths_FileNamesOk ```

:recycle: This comment has been updated with latest results.

[ermshiperete]

Is this different from #305 (other than that the other contains more changes) ?

[papeh]

Is this different from #305 (other than that the other contains more changes) ?

No. I was trying to create discrete PRs as I completed deliverable chunks of work, but GitHub doesn't handle those the same way Gerrit does.