Fix: display Unicode characters in the table of content (#320)

[lcomrade]

I was able to fix issue #320. Now Hebrew and Russian characters are displayed correctly.

[lcomrade]

I run the tests locally:

FAILED test/test_links.py::test_link_alt_text - AssertionError: e35d13f61f2508935ed28c4f17c01308 != 1eb8548fdabde9744bd2f2d22be60143
FAILED test/test_perfs.py::test_intense_image_rendering - Failed: Timeout >40.0s
FAILED test/test_set_date.py::test_setting_old_date - AssertionError: 9a4581eb70460cc4e3dac566650f8152 != 874a8f06bf353ccf49c2e8f5a5d9c704
FAILED test/test_structure_tree.py::test_single_image_structure_tree - AssertionError: assert ('3 0 obj\n'\n '<<\n'\n '/K [4 0 R]\n'\n '/ParentTree 5 0 R\n'\n '/Type /StructTreeRoot\n'\n '...
FAILED test/html/test_html.py::test_html_features - AssertionError: e9d113317a4112d2e25a7387442170b4 != c8e1c7017dbab4a53141d79c4a3b6b42
FAILED test/html/test_html.py::test_html_heading_hebrew - AssertionError: 4bb0f88ef62e47ec61b9e9cf5c504a68 != 8dbdf537d53993450ee9e1e3c831c63e
FAILED test/html/test_html.py::test_html_headings_line_height - AssertionError: 3bec2700217b959be40781b187b4ba79 != d74d76b0e48b306a4c65beb1401a64e1
FAILED test/html/test_html.py::test_html_custom_heading_sizes - AssertionError: 70328b894c059d12f45c31482987a875 != 28f46aa9cc36298809dcfaebd7c20eab
FAILED test/image/alt_text/test_image_alt_text.py::test_alt_text_and_title - AssertionError: 31b52ea25e3ab13ce8b1e9937d6bde44 != fba24ed03fee81813fc7a906a32c6167
FAILED test/image/alt_text/test_image_alt_text.py::test_alt_text_on_two_pages - AssertionError: e06501ca3b56f887e1bb048a299a2df4 != 2e45f6fa060040b672a23afe9880a891
FAILED test/image/image_types/test_insert_images.py::test_insert_jpg_jpxdecode - OSError: encoder jpeg2k not available
FAILED test/image/image_types/test_insert_images.py::test_insert_pillow - AssertionError: f05492ce6debcc275f8563ee814fdc75 != 93b12c307bcd2e5deaf4c69a49679e20
FAILED test/image/image_types/test_insert_images.py::test_insert_bytesio - AssertionError: f05492ce6debcc275f8563ee814fdc75 != 93b12c307bcd2e5deaf4c69a49679e20
FAILED test/outline/test_outline.py::test_simple_outline - AssertionError: 501e3dd5db52ffb3dd02d5b2ffdb408a != 86191c87a72bd290b5a90a6c89b2b106
FAILED test/outline/test_outline.py::test_2_pages_outline - AssertionError: c1e6bf1b3744eebb5b8bd4440f60651e != b2371f799db2b9bcf01d62fe83886cbe
FAILED test/outline/test_outline_html.py::test_html_toc - AssertionError: d109bc05621486b1c7f43198444e4a77 != 17e6fb060a5927b4d11afa3f52f585e7
FAILED test/outline/test_outline_html.py::test_html_toc_2_pages - AssertionError: 218cf9601a299527c56d294b0ac08a24 != 8a4c5359c74d0700ea470236dfddd3ec
FAILED test/outline/test_outline_html.py::test_html_toc_with_h1_as_2nd_heading - AssertionError: 0b605704143c04459c49b17d05823600 != 0e51a5f8ce4217d12784a0322df491c0
FAILED test/outline/test_outline_html.py::test_custom_HTML2FPDF - AssertionError: 5c669aa233acdfb49e83fd07fc967724 != 3f86127217813d5a2e39deb2154e851e
FAILED test/outline/test_outline_serializer.py::test_serialize_outline - AssertionError: assert ('6 0 obj\n'\n '<<\n'\n '/Count 2\n'\n '/First 7 0 R\n'\n '/Last 9 0 R\n'\n '/Type /Outlines...
FAILED test/outline/test_outline_serializer.py::test_serialize_outline_with_headless_hierarchy - AssertionError: assert ('6 0 obj\n'\n '<<\n'\n '/Count 2\n'\n '/First 7 0 R\n'\n '/Last 9 0...
=================================================================== 21 failed, 795 passed, 11 warnings in 78.88s (0:01:18) ====================================================================

For some reason, more tests were failed locally than in GitHub Actions. But most of the failures seem to be caused by a mismatch of hash sums of files. This is because I changed the encoding and new characters appeared in the documents.

[Lucas-C]

Thank you for submitting this @lcomrade!

I was working on a PR myself here: #324

I regenerated all the relevant PDF test reference files as part of this PR

[Lucas-C]

@all-contributors please add @lcomrade for code

Now closing this in favour of #324

[allcontributors]

@Lucas-C

I've put up a pull request to add @lcomrade! 🎉