[#450] Add Util.Main module

Description

Problem: we typically apply 2 functions to main: withUtf8 and displayUncaughtException. Maybe one day we'll have something else. So it's a good idea to group them into a helper function to make sure we won't forget one of them and to make it easier to add another customization later. Also we are using our own displayUncaughtException helper right now, but an equivalent function is exposed from the uncaught-exception package.

Solution:

1. Create Util.Main module with wrapMain that applies both aforementioned wrappers.
2. Use withDisplayExceptionHandler from uncaught-exception. We prefer it over displayUncaughtException from the same library because it's supposed to work better in multi-threaded applications. We don't have many of them, but we have some (e. g. morley-client).
3. Update all Main modules accordingly.

Note: this package is not in Stackage LTS yet, but it's in Nightly and will be added to the next major LTS.

Related issue(s)

Resolves #450 (closed)

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