[RAPPS] Add ExeInZip installer type to support running installers in zip files

[whindsaks]

This feature is to help streamline the installing experience. It will extract the downloaded .zip file to a subfolder in %temp% and execute the the installer. After the installer has completed, the temporary directory is deleted.

For a package like Hxd, simply adding Installer = ExeInZip to the main section is enough because Rapps will default to the first .exe it finds in the root of the extracted zip. For .zip files with a folder structure or multiple .exe files, the file to execute needs to be specified.

For the Royale theme (PR waiting), it would look something like this:

[Section]
Name = Royale
...
Installer = ExeInZip

[ExeInZip]
Exe = Royale Theme for Win XP (2)\Royale Theme for Win XP.exe

Notes:

• WinGet calls this simply zip installer type but they have the concept of NestedInstallerType which we don't.

Testbot runs (Filled in by Devs)

• KVM x86:
• KVM x64:

[Copilot]

Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.

[learn-more]

Sorry, I don't work on rapps anymore.

[HBelusca]

Why do we need yet another instance of the CAppDB? There is one that has been already created when RAPPS has been started. Isn't it possible to use that one instead?

[whindsaks]

1. The "main" instance is lost in loaddlg.cpp (the download dialog).
2. The download stuff happens on a background thread and CAppDB is probably not thread safe.

[HBelusca]

Hmmm ok... It may be of interest in the future to make this appdb a singleton or something like that (so that there's only one running globally for the given rapps instance).

[whindsaks]

I'm not sure if making all its methods thread safe is worth the effort of doing that.

Using a global lock instead would slow down the normal use case just to deal with this rare instance where we want to ask about a single property during install.

[HBelusca]

A comment, but lgtm otherwise.

[HBelusca]

Prefer using wsprintf instead.