Adds timeout command to ghci. Resolves #24040

allows setting timeouts in ghci, as requested in issue #24040

ghci> import Control.Concurrent
ghci> :set timeout 1
ghci> :show timeout 
one second
ghci> threadDelay (1000)
ghci> threadDelay (1000000)
*** Exception: GhciTimedOut
ghci> let a = a
ghci> a 
*** Exception: GhciTimedOut

• if your MR may break existing programs (e.g. touches base or causes the compiler to reject programs), please describe the expected breakage and add the user-facing label. This will run ghc/head.hackage> to characterise the effect of your change on Hackage.
• ensure that your commits are either individually buildable or squashed
• ensure that your commit messages describe what they do (referring to tickets using #NNNN syntax when appropriate)
• have added source comments describing your change. For larger changes you likely should add a [Note][notes] and cross-reference it from the relevant places.
• add a [testcase to the testsuite][adding test].
• updates the users guide if applicable
• mentions new features in the release notes for the next release