Chatterino2: Tab completing in emote menu with case sensitive emotes can give wrong emote

[ligos96]

Describe the bug
Tab completing in the emote menu when there is multiple emotes with the same name but different casings can autocomplete to the wrong emote.

To reproduce
Using MEGALUL and MegaLUL as an example.

1. Type :megal to bring up emote menu
2. Select MEGALUL and press TAB (Note: works as expected if you press ENTER instead)
3. Selected emote is MegaLUL instead of MEGALUL

Screenshots

Chatterino version
Chatterino 2.2.2 (commit 07fc0c3ad)

Operating system
Windows 10

[daiexd]

can replicate on Windows 10 / Chatterino Nightly 2.2.3-beta (commit 466d85c90, 25.10.2020)

note: seems to only be an issue with emotes that are spelt the same but with different capitalizations.

[dnsge]

duplicate of #1962