Fix: get app dir from native part to initialize Gno's structures

[D4ryl00]

This PR fixes a crash when I try to run the gnoboard app on Android and on some iOS devices.
The Gno configuration struct BaseOptions needs a dataDir path to create files. The default HomeDir() function provided in tm2/pkg/crypto/keys/client/common.go to get that path doesn't work on mobile and causes a panic, because some environment variables are not set on mobile.
The HomeDir function is called every time the tm2/pkg/crypto/keys/client subfolder is imported because of the global variable DefaultBaseOptions that calls Homedir. To avoid the call of the HomeDir function that calls a panic, we duplicated BaseOptions in gnomobile, so the tm2/pkg/crypto/keys/client is no more imported and we provided it the app container path directory from the Android/iOS native parts.

This PR also updates the go.mod to use the latest version of Gno that fixes the ambiguous import of the btcd dependencies.

[jefft0]

The gnoboard example works for me on Android and iOS simulators.