Bump js-slang and update infinite loop detector

[JoeyChenSmart]

Description

Bump js-slang to 0.5.12.

The new version of js-slang implements an overhauled infinite loop detector which breaks certain features depending on the old implementation (namely the reporting infinite loop to sentry feature).

The new reporting feature can be turned on/off depending on whether the user has given approval or not.
This approval flag (state.session.experimentApproval in the state) is set to 'false' as default.
A future change should check for the user's given approval status and set this flag accordingly.

Also, as discussed in the meeting, we will only show the 'enhanced' infinite loop errors 50% of the time.

Type of change

• Breaking change (fix or feature that would cause existing functionality to not work as expected)

How to test

Run an infinite loop into the playground. The new error should show up 50% of the time. Refresh the page to 'reroll' for different results.

Checklist

• I have tested this code

[coveralls]

Pull Request Test Coverage Report for Build 1066740485

• 15 of 15 (100.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.3%) to 29.706%

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Totals
Change from base Build 1066010755:	-0.3%
Covered Lines:	3164
Relevant Lines:	9780

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💛 - Coveralls

[martin-henz]

Looks fine