Update tx filters to work with an array of strings

[buberdds]

We can provide multiple values to Nexus filter query param. Our API layer expect filter to be an array not a string.
This probably requires changes in axios paramsSerializer or orval.

Fix temp workaround introduced in https://github.com/oasisprotocol/explorer/pull/1781/files

[csillag]

Because performance reasons, Nexus decided to drop support for accepting multiple values here, now it's just a single value. So I guess we can close this now.

In any case, the required custom paramSerializer has been implemented as part of #2012 (for sending a word list for flexible multi-world search), so if this issue comes up again, we can just add paramsSerializer: paramSerializerWithComma to the request.

[lukaw3d]

Opened #2015 to make a general solution