Fix insufficient number width allocated when using -print-lines

[natsukagami]

Fix #22505

The main problem of the crash was the combination of -print-lines and -explain,
along with the rare case where we need to display the 9-10 range for the line-range 9..10
(which was represented in the codebase as 8..9), that was given insufficient number width to begin with.

Alongside the change, I also added newlines before the TypeMismatch explanation's tree output.
This can be debated, but without it -explain -print-lines looks like this:

-- [E007] Type Mismatch Error: /tmp/tmp.jNWSWbUu4O/src/main/scala/Main.scala:4:21 
 4 |  val tmp: List[B] = for (
   |                     ^
   |                     Found:    IndexedSeq[B]
   |                     Required: List[B]
 5 |    i <- (0 to l.size - 1);
 6 |//       j <- (i + 1 to l.size - 1);
 7 |    a <- (0 to l(i).size - 1);
 8 |//      b   <- (0 to l(j).size - 1);
 9 |    res <- f(l(i)(a))
10 |  ) yield res
   |----------------------------------------------------------------------------
   | Explanation (enabled by `-explain`)
   |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
   |
   | Tree:   5|intWrapper(0).to(l.size - 1).flatMap[B]((i: Int) =>
   |     7|  intWrapper(0).to(l.apply(i).size - 1).flatMap[B]((a: Int) =>
   |  9-10|    f.apply(l.apply(i).apply(a)).map[B]((res: B) => res))
   | )
   | I tried to show that
   |   IndexedSeq[B]
   | conforms to
   |   List[B]
   | but none of the attempts shown below succeeded:
   |
   |   ==> IndexedSeq[B]  <:  List[B]  = false
   |
   | The tests were made under the empty constraint
    ----------------------------------------------------------------------------

The error looks much nicer (imo!) with the change:

   |----------------------------------------------------------------------------
   | Explanation (enabled by `-explain`)
   |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
   |
   | Tree:
   |
   |     5|intWrapper(0).to(l.size - 1).flatMap[B]((i: Int) =>
   |     7|  intWrapper(0).to(l.apply(i).size - 1).flatMap[B]((a: Int) =>
   |  9-10|    f.apply(l.apply(i).apply(a)).map[B]((res: B) => res))
   | )
   |
   | I tried to show that
   |   IndexedSeq[B]
   | conforms to
   |   List[B]
   | but none of the attempts shown below succeeded:
   |
   |   ==> IndexedSeq[B]  <:  List[B]  = false
   |
   | The tests were made under the empty constraint
    ----------------------------------------------------------------------------

(I have no idea how to add a line range to the last ), perhaps something can be changed
in the .show implementation, but it seems complicated...)

Changes

• Change max number width to accomodate the full number range
• Put the TypeMismatch explanation tree on its own lines