Berry string.format() now automatically converts type according to format

[s-hadinger]

Description:

Applying upstream PRs:

• Add be_baselib.h berry-lang/berry#342
• string.format automatic conversion berry-lang/berry#343

string.format() now automatically tries to convert to int/real/string according to the format:

• if %d/i/o/u/x/X/c, an explicit call to int() is made to convert to int
• if %e/E/f/g/G, an explicit call to real() is made
• if %s an explicit call to str() is made

# Example:

string.format("%i", "3")  # now return '3' instead of ''

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.2.0.10
• I accept the CLA.

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