Kql query formatting

[FlorianBracq]

Minor changes to improve formatting of KQL queries:

• Add a space to the list separator (", " instead of ",")
• Remove blank lines generated from variable" placeholder" that are not defined.
  For instance:

MyTable
{timeCondition}
| where key == "value"

would generate with the current version

MyTable

| where key == "value"

instead of

MyTable
| where key == "value"