cli: Fix rendering of long integers

Recent changes to the human-readable rendering of outputs and console
values led to long integer values being presented in scientific
notation (e.g. 1.2345678e+07). While technically correct, this is an
unusual way to present integer values.

This commit changes the formatting mode to 'f', which never uses
scientific notation and displays integer values as a sequence of digits
instead (e.g. 12345678).

repl/format.go

@@ -52,7 +52,7 @@ func FormatValue(v cty.Value, indent int) string {
 			return strconv.Quote(v.AsString())
 		case cty.Number:
 			bf := v.AsBigFloat()
-			return bf.Text('g', -1)
+			return bf.Text('f', -1)
 		case cty.Bool:
 			if v.True() {
 				return "true"

repl/format_test.go

@@ -89,10 +89,22 @@ EOT_`,
 			cty.NumberIntVal(5),
 			`5`,
 		},
+		{
+			cty.NumberIntVal(1234567890),
+			`1234567890`,
+		},
 		{
 			cty.NumberFloatVal(5.2),
 			`5.2`,
 		},
+		{
+			cty.NumberFloatVal(123456789.0),
+			`123456789`,
+		},
+		{
+			cty.NumberFloatVal(123456789.01),
+			`123456789.01`,
+		},
 		{
 			cty.False,
 			`false`,