Implement `Process` to match the JavaScript API

[Xoffio]

We can use the JavaScript API docs as a goal -> https://frida.re/docs/javascript-api/#process

• Process.id done in adding process #182
• Process.arch
• Process.platform done in adding process #182
• Process.pageSize
• Process.pointerSize
• Process.codeSigningPolicy done in adding process #182
• Process.mainModule done in adding process #182
• Process.getCurrentDir() done Added more function for Process #188
• Process.getHomeDir() done Added more function for Process #188
• Process.getTmpDir() done Added more function for Process #188
• Process.isDebuggerAttached() done Added is_debugger_attached to Process #225
• Process.getCurrentThreadId() done Added more function for Process #188
• Process.enumerateThreads() done Add threads and thread enumeration #213
• Process.attachThreadObserver(callbacks)
• Process.runOnThread(id, callback)
• Process.findModuleByAddress(address), Process.getModuleByAddress(address), Process.findModuleByName(name), Process.getModuleByName(name)
• Process.enumerateModules() done 006af61
• Process.attachModuleObserver(callbacks)
• Process.findRangeByAddress(address), getRangeByAddress(address)
• Process.enumerateRanges(protection|specifier) done in adding process #182
• Process.enumerateMallocRanges()
• Process.setExceptionHandler(callback)

We can keep this issue open to track the progress and close it once its done :)