[SR-15932] Linking to the same URL with different custom link titles uses one of those titles for both instances

[franklinsch]

Previous ID	SR-15932
Radar	rdar://85876832
Original Reporter	@franklinsch
Type	Improvement

Additional Detail from JIRA

Votes	0
Component/s	Swift-DocC
Labels	Improvement
Assignee	None
Priority	Medium

md5: 11a6c2d379f9bb62ef931ef2102ceac6

Issue Description:

Linking to the same URL with different custom link titles in Tutorial content sometimes uses one of those titles for both instances

To reproduce, create a tutorial file and include the link `[TitleA](https://swift.org)` in one `@ContentAndMedia` directive, and `[TitleB](https://swift.org)` in another `@ContentAndMedia` directive.

You'll see that both links in the rendered content use the name `TitleA` or `TitleB`.