Add support for enrollment links in tlsmirror

[xiaokangwang]

(Machine Generated Summary:)

This pull request introduces support for strict, MIME-typed data URL encoding and decoding of TLS mirror enrollment links, along with a CLI tool and comprehensive tests. The changes ensure that enrollment links are handled in a robust, well-defined way, and integrate this handling into both client and server configuration paths.

Enrollment Link Handling and CLI Integration:

• Added LinkFromAny and AnyFromLink functions in enrollmentlink.go to convert between protobuf Any messages and strict data URLs with the MIME type application/vnd.v2ray.tlsmirror-enrollment. Only data URLs with this exact MIME type and base64 encoding are accepted.
• Introduced a new CLI command in clicommand/enrollmentlink_cli.go for converting between JSON and link formats, supporting stdin/stdout and file I/O, and registering the command with the engineering CLI.
• Updated both client (client.go) and server (server.go) initialization to parse bootstrap ingress/egress URLs using the new strict AnyFromLink function, rejecting empty or invalid URLs and converting them to protobuf Any configs. [1] [2]

Testing and Validation:

• Added extensive tests in enrollmentlink_test.go to validate round-trip encoding/decoding, strictness of MIME type and encoding, rejection of legacy/invalid formats, and handling of large payloads and extra parameters.

Project Integration:

• Registered the new CLI command in the main build by updating the imports in main/distro/all/all.go.