Use existing HTTP client on Telegram initialisation

Fix logging deprecation output

[skip ci]

Update README and CHANGELOG

InputMedia methods fixed

API 4.3 - Seamless Telegram Login

Prevent system commands from being called by the user directly

Use PSR-3 LoggerInterface to allow custom logging implementations.

Smarten up subEntities and return empty array for Entity items

Housekeeping git meta and tests, custom issue templates

Smaller code and docblock fixes

[skip ci]

Update funding and donation/support infos.

[skip ci]

Add Tidelift for security disclosures.
[skip ci]