[Let's Encrypt]: Add CA selection, enhance compatibility for Cert installation

[ScortYang]

This pull request introduces significant improvements to the ACME certificate management scripts and web UI, primarily adding support for selecting the Certificate Authority (CA) between Let's Encrypt and ZeroSSL, with email validation for ZeroSSL, and enhancing certificate installation and cleanup logic. The changes also include UI refinements and minor bug fixes.

Major new features and enhancements:

Support for ZeroSSL and CA selection:

• Added support for selecting the CA (Let's Encrypt or ZeroSSL) in both the backend (acme_config.sh) and frontend (Module_acme.asp), including logic to normalize and validate the CA choice and handle ZeroSSL account registration with email validation. [1] [2] [3] [4] [5] [6]
• Updated the certificate issuance process to use the selected CA and ensure proper registration and setup before issuing certificates.

Certificate installation and cleanup improvements:

• Enhanced the certificate installation logic to install certificates and keys into multiple paths using --fullchain-file for compatibility, and updated the cleanup process to remove additional files and restart relevant services. [1] [2]

UI and usability improvements:

Web UI changes:

• Added CA selection dropdown and ZeroSSL email input to the web interface, with dynamic visibility and client-side validation for email format. [1] [2] [3]
• Improved parameter handling in the frontend to support new CA-related fields and ensure default values. [1] [2]

Minor fixes and refactoring:

• Updated script and style includes for consistency and fixed a minor link bug in the changelog URL. [1] [2]
• Cleaned up CSS and removed redundant background gradients. [1] [2]
• Fixed a BOM (Byte Order Mark) issue in the HTML file.

Other changes:

Environment and configuration:

• Set DOH_USE=3, which is Aliyun DOH, in the environment configuration for DNS-over-HTTPS usage.