CCITTFaxStream parser: resolve xref if needed

Fixes #5243
Handtool: Remove focus from previous node on click

"This commit fixes the issue that a focused element cannot lose
focus when the draggable element is clicked."
https://github.com/Rob--W/grab-to-pan.js/commit/11c368f97cebe19

Steps to reproduce/verify:
1. Enable the hand tool (e.g. by using the H shortcut)
2. Click on the Page number input.
3. Click or drag the PDF canvas.
4. Observe that the page number input is still focused.
   Consequently, the hand tool cannot be disabled using the H shortcut.
Merge pull request #5259 from Rob--W/handtool-unfocus

Handtool: Remove focus from previous node on click
Add basic support for ZapfDingbats
Add ZapfDingbats testcase
Merge pull request #5251 from Snuffleupagus/dingbats

Add basic support for ZapfDingbats
Merge pull request #5249 from Rob--W/issue-5243

CCITTFaxStream parser: resolve xref if needed
Add more cases to |mapSpecialUnicodeValues| to fix the rendering of various Symbol encoded brackets
Add |SpecialPUASymbols| map and refactor |mapSpecialUnicodeValues|