Kill gnosisSafe.js by upgrading @safe-global libs

[jmrossy]

Problem

Due to problems with the @safe-global libs, code to interact with them had to be written in JS instead of TS:
#3717

The safe team has allegedly improved their libs. If so, we can potentially remove this hack.

[paulbalaji]

future readers: note that a reason we haven't been able to update the libs is because newer versions require ethers v6, and we are still using ethers v5