* chore(extension.ts): add interface for Gitea error response
* feat(extension.ts): add global variables for status bar icons
* feat(extension.ts): add helper function to check if a folder is a Git repository
* feat(extension.ts): add helper function to check if the remote repository is a Gitea instance
* feat(extension.ts): create Gitea pull request function
* feat(extension.ts): add function to clone Gitea repository
* feat(extension.ts): add function to add status bar icon
* feat(extension.ts): add function to configure Gitea
* feat(extension.ts): add function to get open pull requests
* feat(extension.ts): add function to show open pull requests
* feat(extension.ts): add function to update PR status bar item
* feat(extension.ts): activate the plugin and register commands
* feat(extension.ts): create status bar icon and start updater