LVGL add support for TrueType fonts via FreeType library

[s-hadinger]

Description:

Support for TrueType fonts is disabled by default and requires #define USE_LVGL_FREETYPE. It uses a default glyph cache size (in PSRAM) of 16KB that can be increased.

This uses the following libraries:

• FreeType 2.10.4 https://www.freetype.org/
• lv_lib_freetype customized for Tasmota https://github.com/lvgl/lv_lib_freetype

Note: this works better with large Flash (16MB) or SD Cards since TTF fonts typically are 100KB sized.

Note2: FreeType uses 24KB of stack which is beyond the standard 8KB stack. For this reason a secondary FreeRTOS task is created with 24KB of stack size and used when calling FreeType glyph rendering engine.

Example:

#- font playa.ttf -#
playa80 = lv.load_freetype_font("playa.ttf", 80, 0) #- font 'playa.ttf' in file-system, size 80, style plain -#
label.set_style_local_text_font(lv.OBJ_PART_MAIN, lv.STATE_DEFAULT, playa80)

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 on Tasmota core ESP8266 V.2.7.4.9
• The code change is tested and works with core ESP32 V.1.0.6
• I accept the CLA.

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