Remove duplicate entries from lab file

[PeterTillema]

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What's wrong, and with what software version?

Operating System: Windows 10
CEmu version: CEmu v1.3 (git: 87c3b43)
**Describe your issue:
If you load a lab file, it might happen there are several duplicate entries with the same address and value. This is displayed as (value|value|value|value|value|value|otherLabel), which is quite annoying. So it would be nice if duplicate names would be removed, such that the above one becomes (value|otherLabel) which is already a lot cleaner.

What are the steps to reproduce this issue?

1. Create a lab file using symbol_table.inc from jacobly's fasmg-ez80
2. Load it in the debugger
3. Watch

Any logs, error output, screenshot, other comments...?