Berry RS256 crypto algorithm (RSASSA-PCKS1_v1-5 with SHA256) used for JWT

[s-hadinger]

Description:

Expose in Berry RS256 primitive from BearSSL, used in JWT. Example will be added to documentation. See #18758

Requires #define USE_BERRY_CRYPTO_RSA

Checklist:

• The pull request is done against the latest development branch
• Only relevant files were touched
• Only one feature/fix was added per PR and the code change compiles without warnings
• The code change is tested and works with Tasmota core ESP8266 V.2.7.4.9
• The code change is tested and works with Tasmota core ESP32 V.2.0.9
• I accept the CLA.

NOTE: The code change must pass CI tests. Your PR cannot be merged unless tests pass