add MARS connection for aioodbc

add MARS connection for aioodbc

on jenkins main we are getting a lot of connection busy with
other results, which we assume is due to the thread-pool based approach
of aioodbc not being very solid.

MARS is described at:

https://stackoverflow.com/questions/9017264/why-only-some-users-get-the-error-connection-is-busy-with-results-for-another
https://learn.microsoft.com/en-us/sql/relational-databases/native-client/features/using-multiple-active-result-sets-mars?view=sql-server-ver16

not clear why the name of the parameter is different in those two
articles. using a totally made up parameter doesn't raise any error,
so it's not clear if this works at all.

Change-Id: I8e437e9f46c1c070c5102a24d7d82a912e8b5145