(iOS) Parse existing post_install block in Podfile

[dpa99c]

As highlighted in this comment, if another plugin (e.g. cordova-plugin-ble-central) is present in the Cordova project (alongside this one) which injects a post_install block into the Podfile, this plugin will currently skip the step to inject its own post_install block, potentially causing the build to fail on Xcode 14+ because the steps in that block are necessary for a successful build.

Multiple post_install blocks in a Podfile are not supported, so this plugin would need to detect and parse the hierarchy of an existing post_install block in order to inject its own steps into the existing hierarchy.

[dpa99c]

I thought I might ask OpenAI's ChatGPT to help out 😲