Update BBS interop tests to support latest Go and Node versions

[DRK3]

The check_bbs_interop.sh script used to copy the wasm_exec.js file directly from $GOROOT/misc/wasm/wasm_exec.js. However, the latest version of Go works differently in that the functionality in wasm_exec.js has been reworked to separate out Node-specific code into a separate file ($GOROOT/misc/wasm/wasm_exec_node.js). These changes break our BBS interop testing code. As an interim solution, in #3418 I manually copied the old wasm_exec.js file in our project instead of copying the latest from $GOROOT/misc/wasm/wasm_exec.js. We should find a way to rework our BBS interop testing code to work with the latest verison.

Additionally, the current BBS interop tests don't work on the latest Node version (I tested with 16.17.0 and it failed). The CI is currently using 12.14.x, which does work (with the older script I mentioned above). We should also update the code to work with the latest Node.