Replace ! in filenames when converting to JS identifiers

[joshuamiller]

When using Closure to emit ES5 code for ClojureScript, the source filename of the input code can be in a jar, such as file:/Users/myuser/.m2/repository/org/clojure/google-closure-library/0.0-20230227-c7c0a541/google-closure-library-0.0-20230227-c7c0a541.jar!goog/log/log.js. The ! is not replaced when converting this filename to a JS identifier, resulting in the following input/output pair:

goog.log.Level = class Level { constructor() ... }

file_$Users$myuser$_m2$repository$org$clojure$google_closure_library$0_0_20201211_3e6c510d$google_closure_library_0_0_20201211_3e6c510d_jar!$goog$log$log$classdecl$var0 = function(name, value) { ...

Note that the variable name has ! in it, which does not parse.

This PR adds ! to the list of special characters to replace so that jar-sourced input files can produce legal ES5 output.

[mhausner]

Chinthoorie, can you please accept this PR?