* v5: Health Check & LeastLoad Strategy (rebased from 2c5a71490368500a982018a74a6d519c7e121816)
Some changes will be necessary to integrate it into V2Ray
* Update proto
* parse duration conf with time.Parse()
* moving health ping to observatory as a standalone component
* moving health ping to observatory as a standalone component: auto generated file
* add initialization for health ping
* incorporate changes in router implementation
* support principle target output
* add v4 json support for BurstObservatory & fix balancer reference
* update API command
* remove cancelled API
* return zero length value when observer is not found
* remove duplicated targeted dispatch
* adjust test with updated structure
* bug fix for observer
* fix strategy selector
* fix strategy least load
* Fix ticker usage
ticker.Close does not close ticker.C
* feat: Replace default Health Ping URL to HTTPS (#1991)
* fix selectLeastLoad() returns wrong number of nodes (#2083)
* Test: fix leastload strategy unit test
* fix(router): panic caused by concurrent map read and write (#2678)
* Clean up code
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Co-authored-by: Jebbs <qjebbs@gmail.com>
Co-authored-by: Shelikhoo <xiaokangwang@outlook.com>
Co-authored-by: 世界 <i@sekai.icu>
Co-authored-by: Bernd Eichelberger <46166740+4-FLOSS-Free-Libre-Open-Source-Software@users.noreply.github.com>
Co-authored-by: 秋のかえで <autmaple@protonmail.com>
Co-authored-by: Rinka <kujourinka@gmail.com>
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