lift TrueTypeFontUnicode.includeCidSet flag up to BaseFont to make it publicly accessible (#1041)

[zyro23]

Description of the new Feature/Bugfix

this is a follow-up to #1045 which added a new TrueTypeFontUnicode.includeCidSet flag.
but due to the class TrueTypeFontUnicode being package private, that class cannot be used directly in consumer application code (i.e. to downcast BaseFont), meaning the flag is not accessible.
this commit lifts the flag along with its getter/setter up to BaseFont to make it publicly accessible.

Related Issue: #1041

Unit-Tests for the new Feature/Bugfix

• Unit-Tests added to the added feature

Compatibilities Issues

n/a

Testing details

@andreasrosdal sorry for not spotting this right away.. missed it as the unit-test resides in the same package..
i hope this approach makes sense to you, too - i did not want to change TrueTypeFontUnicode visibility. added some javadoc.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud

[andreasrosdal]

Thank you. More pull requests to improve OpenPDF is welcome.