Added Simple Filtering and Property Comparison

[Phando]

This PR introduces two new functions (and their overloads).

  bool hasPropertyEqual(const char* key,  const char* value) const;  
  bool hasPropertyEqual(const char* key,  const JSONVar& value) const;  
  bool hasPropertyEqual(const String& key,  const String& value) const;  
  bool hasPropertyEqual(const String& key,  const JSONVar& value) const;  

  JSONVar filter(const char* key, const char* value) const;
  JSONVar filter(const char* key, const JSONVar& value) const;
  JSONVar filter(const String& key, const String& value) const;
  JSONVar filter(const String& key, const JSONVar& value) const;

hasPropertyEqual returns true if the JSONVar has a property with a value that matches value.

filter returns an array containing all the objects who have a property matching value. If an object and not an array is passed to filter and there is a match, the original object is returned inside an array.

This PR should cut down on repetitive JSONVar parsing code.

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[github-actions[bot]]

Memory usage change @ 1da99788176f26ed6db2a97e88a8038597b7da2b

Board	flash	%	RAM for global variables	%
arduino:avr:leonardo	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:avr:mega	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:avr:nano	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:avr:yun	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:mbed_edge:edge_control	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:mbed_nano:nano33ble	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:mbed_nano:nanorp2040connect	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:mbed_portenta:envie_m4	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:mbed_portenta:envie_m7	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:megaavr:nona4809	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:megaavr:uno2018	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:sam:arduino_due_x_dbg	0 - 0	0.0 - 0.0	N/A	N/A
arduino:samd:arduino_zero_edbg	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:mkrzero	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:samd:nano_33_iot	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0

Click for full report table

Board|examples/JSONArray
flash|%|examples/JSONArray
RAM for global variables|%|examples/JSONKitchenSink
flash|%|examples/JSONKitchenSink
RAM for global variables|%|examples/JSONObject
flash|%|examples/JSONObject
RAM for global variables|% -|-|-|-|-|-|-|-|-|-|-|-|- arduino:avr:leonardo|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 arduino:avr:mega|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 arduino:avr:nano|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 arduino:avr:yun|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 arduino:mbed_edge:edge_control|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 arduino:mbed_nano:nano33ble|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 arduino:mbed_nano:nanorp2040connect|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 arduino:mbed_portenta:envie_m4|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 arduino:mbed_portenta:envie_m7|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 arduino:megaavr:nona4809|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 arduino:megaavr:uno2018|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 arduino:sam:arduino_due_x_dbg|0|0.0|N/A|N/A|0|0.0|N/A|N/A|0|0.0|N/A|N/A arduino:samd:arduino_zero_edbg|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 arduino:samd:mkrzero|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 arduino:samd:nano_33_iot|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0

Click for full report CSV

``` Board,examples/JSONArray
flash,%,examples/JSONArray
RAM for global variables,%,examples/JSONKitchenSink
flash,%,examples/JSONKitchenSink
RAM for global variables,%,examples/JSONObject
flash,%,examples/JSONObject
RAM for global variables,% arduino:avr:leonardo,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:avr:mega,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:avr:nano,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:avr:yun,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:mbed_edge:edge_control,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:mbed_nano:nano33ble,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:mbed_nano:nanorp2040connect,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:mbed_portenta:envie_m4,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:mbed_portenta:envie_m7,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:megaavr:nona4809,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:megaavr:uno2018,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:sam:arduino_due_x_dbg,0,0.0,N/A,N/A,0,0.0,N/A,N/A,0,0.0,N/A,N/A arduino:samd:arduino_zero_edbg,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:samd:mkrzero,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:samd:nano_33_iot,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 ```