MbedTLS and cURL update

[JanneKiiskila]

Mbed Edge pull request

Description

• Update Mbed TLS to version 2.28.2, update repo domain to Mbed-TLS.
• Update cURL to version 7.78.0.

Test instructions

Build, connect, FOTA.

Check list

API change(s)

• [x] Not applicable.
• [ ] API is backwards compatible.
• [ ] API documentation is updated.

Example applications updated

• [x] Not applicable.

  Changelog

• [x] CHANGELOG.md updated.

[JanneKiiskila]

Rebased, force pushed.

[JanneKiiskila]

Rebased, force pushed.