CDC: Missing documented stats kv_ep_magma_history_time_evicted_bytes and kv_ep_magma_compactions

Whilst reviewing (and testing) the documentation for change-streams I noted that the following statistic, which is in the code and documentation was not being returned.

• kv_ep_magma_history_time_evicted_bytes
• kv_ep_magma_compactions stats

This has been tracked down to a coding error in a list of strings which make up the list of valid magma stats.

   constexpr std::array<std::string_view, 53> statNames = {

            {"magma_HistorySizeBytesEvicted",

             "magma_HistoryTimeBytesEvicted"  <--- missing comma

             "magma_NCompacts",

Note the missing comma is the error, which also impacts on magma_NCompacts

The fix is to add a comma

This is a regression for the kv_ep_magma_compactions stat