Fix support custom URLs for S3 storage

[finagin]

• Laravel Version: ≥5.5.21
• PHP Version: not relevant
• Database Driver & Version: not relevant

Description:

AWS-SDK-S3 don't support url. Needs endpoint configuration variable.

This way works only for FilesystemAdapter::url, but not for other methods like exists, put, temporaryUrl etc. with S3 adapter.

Steps To Reproduce:

1. In config/filesystems.php set s3.url not AWS S3 like https://hb.bizmrg.com
2. Call Storage::cloud()->put('test/test.txt', 'cloud');

Steps To Solution:

1. Revert [5.5] Support custom URLs for AWS storage #22037
2. Fix Support custom URLs for AWS storage laravel#4483 change url to endpoint

[finagin]

laravel/laravel#4686 and #24593 must be merged together

[driesvints]

Going to close this as the PRs were closed as well. I think it's best if you lay down your use case at https://github.com/laravel/ideas first to gather support and try again with the info Taylor has requested.