feat: Add x/precisebank module basic setup

[drklee3]

Description

• Add initial setup and empty genesis type for x/precisebank
• Basic tests with mostly empty values, to be filled out with additional implementation

Checklist

• Changelog has been updated as necessary.

[pirtleshell]

nit: can we add a test for this similar to the one we have in x/community?

kava/x/community/module_test.go

Lines 14 to 22 in 3c53e72

	func TestItCreatesModuleAccountOnInitBlock(t *testing.T) {
	tApp := app.NewTestApp()
	ctx := tApp.NewContext(true, tmproto.Header{Height: 1})
	tApp.InitializeFromGenesisStates()
	accKeeper := tApp.GetAccountKeeper()
	acc := accKeeper.GetAccount(ctx, authtypes.NewModuleAddress(types.ModuleName))
	require.NotNil(t, acc)
	}