bug(developer): wrong output in test area for minimal ldml keyboard

[ermshiperete]

Use the following useless one-key keyboard:

<?xml version="1.0"?>
<keyboard3 xmlns="https://schemas.unicode.org/cldr/45/keyboard3" locale="en" conformsTo="45">
  <info author="eb" name="LdmlOneKey"/>
  <version number="1.0.0"/>
  <keys>
    <!-- no keys listed, keys-Latn-implied.xml will be implicitly imported -->
  </keys>

  <layers formId="us">
    <layer id="base">
      <row keys="gap 1" />
    </layer>
  </layers>
</keyboard3>

In Keyman Developer, compile the keyboard, then "Test Keyboard". In the test area, press 1 Enter 1.

Expected output (| being the IP):

1
1|

Actual output:

1

1|

Expected grid output (| being the green current location marker):

U+0031 U+000D U+000A U+0031 |

Actual grid output:

U+0031 U+000D U+000A U+000D | U+000A U+0031 U+000D U+000A 

Screenshot:

Keyman 18.0.245

[ermshiperete]

Things work correctly in Notepad, and for a similar .kmn keyboard.

For .kmn keyboards the test area only shows U+000D instead of U+000D U+000A.

Things get worse when typing more 1 - 1s get duplicated.