Berry bytes solidification

[s-hadinger]

Description:

Berry is now able to solidify bytes instances, which opens the door for more flash size optimization.

Example:

class DemoBin
    static var b1 = bytes("DEADBEEF")
end

import solidify
solidify.dump(DemoBin)

Output is:

extern const bclass be_class_DemoBin;

/********************************************************************
** Solidified class: DemoBin
********************************************************************/
be_local_class(DemoBin,
    0,
    NULL,
    be_nested_map(1,
    ( (struct bmapnode*) &(const bmapnode[]) {
        { be_const_key(b1, -1), be_const_bytes_instance(DEADBEEF) },
    })),
    (bstring*) &be_const_str_DemoBin
);

As expected, the solidified bytes instance is read-only.

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.2.7.6
• The code change is tested and works with Tasmota core ESP32 V.3.0.0
• I accept the CLA.

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