Add test described by #233

[alt-romes]

No description provided.

[alt-romes]

Interestingly, when I set two breakpoints by line it crashes on the second breakpoint it sends, with:

      Imported module bindings available in evaluate context (issue #233):     FAIL (0.49s)
        test/haskell/Test/DAP/Init.hs:173:
        Aborted debugger thread: ghc-internal:GHC.Internal.Exception.ErrorCall:

        IntMap.!: key 14 is not an element of the map

        IPE backtrace:
          Development.Debug.Adapter.Interface.handleAbort (hdb/Development/Debug/Adapter/Interface.hs:31:18-27)
          DAP.Types. (:)
          Data.Aeson.KeyMap. (:)
          DAP.Types.explicitToField (src/Data/Aeson/Types/ToJSON.hs:361:5-50)
          Data.Aeson.KeyMap. (:)
          Data.Aeson.KeyMap. (:)
          DAP.Adaptor. (:)
          Data.Aeson.Encode.Pretty.encodePrettyToTextBuilder' (./Data/Aeson/Encode/Pretty.hs:160:64)
          Data.Aeson.Encode.Pretty.encodePretty' (./Data/Aeson/Encode/Pretty.hs:148:48-78)
          DAP.Adaptor. (:)
          DAP.Internal.withLock (src/DAP/Internal.hs:23:43-59)
          DAP.Internal. (:)
          DAP.Adaptor.logWithAddr (src/DAP/Adaptor.hs:114:28-32)
          DAP.Adaptor. (:)
          DAP.Event.sendOutputEvent (src/DAP/Event.hs:110:38-52)
          Development.Debug.Adapter.Interface.>> (src/DAP/Types.hs:251:7-11)
          Development.Debug.Adapter.Breakpoints.>>= (src/DAP/Types.hs:251:7-11)
          DAP.Adaptor.runAdaptorRequest (src/DAP/Adaptor.hs:486:50)
          DAP.Server.serviceClient.lcl' (src/DAP/Server.hs:147:18-45)
        HasCallStack backtrace:
          error, called at libraries/containers/containers/src/Data/IntMap/Internal.hs:639:17 in containers-0.8-8df4:Data.IntMap.Internal

I'll have to look next week why setting a second breakpoint via the testsuite has this disastrous result.
Also find where this error message is coming from and make it easier to debug next time.

[alt-romes]

(This is failing because of #297)

[alt-romes]

I created #299 as a follow up