Make logging to content page console safer

[joelpurra]

Reported by @Rob--W:

3. Execute.logToPage and Execute.logToPageWithColor generate and run JavaScript code in an unsafe way:
   Your sanitization logic,
   .map((arg) => arg.replace(/\/g, "\\"))
   .map((arg) => arg.replace(/"/g, "\""))
   .map((arg) => arg.replace(/\n/g, "\\n"))
   .map((arg) => "${arg}")
   .join(", ");
   can be bypassed by strings containing carriage returns (\r) or line/paragraph separators (\u2028 and \u2029). In your specific case, the impact is limited to a JavaScript error being thrown in the console.
   To safely generate JavaScript code for use with browser.tabs.executeScript, use JSON.stringify:
   .map((arg) => JSON.stringify(arg))
   .join(", ");

[joelpurra]

Sure. Implemented it in the preexisting _variableToSafeString(). Thanks!

[joelpurra]

See at least a658cd2, ac03536, 9743e30.

[joelpurra]

See also #7.