Add LogtailClient curl connection timeout and timeout

[vzikmund]

Due to experience with occasionally slow Logtail endpoint, I decided to add connection timeout and timeout parameters to cURL settings. Timeouts are optional and set to 5 seconds by default - it should be enough for ordinary behaviour.

I wasn't able to run composer install because of composer.lock file, which was created with php8. My environment is running in php7.4 which sould be sufficient according to requirements in composer.json file. Therefore I removed unnecessarycomposer.lock file. I also added required ext-curl into the composer.json.

[PetrHeinz]

Hello @vzikmund, thank you for your contribution 🙌

Customizable timeouts definitely make sense to me and are an awesome addition for making logging more stable. I took the liberty of changing the unit from seconds to milliseconds (to allow finer control). Please take care when upgrading from your fork if you ended up changing the defaults in your application 🙏

I'll make sure to release the change in both 2.x and 3.x to keep things consistent.