Refactor/rules handling

[pr0gramista]

Description

The problem with rules is that it is impossible to figure out if rules have actually been changed between builds and because rules have been a part of field data it was considered as a change for that field.

This allowed to easily get into an infinite rendering loop.

This PR will separate field rules from field data, thus providing the ability to prevent unnecessary build triggers and ignore rules changes since those are not actually needed for rendering and are not really a part of the state either.

Updating rules by programmatically on SuperForm instance never made much sense for fields that have their widgets so there is no need to implement listening on that. If there would be a need for that it would probably be exposed via onRulesChange callback similar to onChange

Consider this bug fix as a minor breaking change.

Type of Change

• ✨ New feature (non-breaking change which adds functionality)
• 🛠️ Bug fix (non-breaking change which fixes an issue)
• ❌ Breaking change (fix or feature that would cause existing functionality to change)
• 🧹 Code refactor
• ✅ Build configuration change
• 📝 Documentation
• 🗑️ Chore

[codecov]

Codecov Report

Merging #26 (ccaaf49) into master (1f7a543) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master      #26   +/-   ##
=======================================
  Coverage   99.83%   99.84%           
=======================================
  Files          13       13           
  Lines         624      645   +21     
=======================================
+ Hits          623      644   +21     
  Misses          1        1           

Impacted Files	Coverage Δ
lib/src/fields/checkbox_super_form_field.dart	100.00% <100.00%> (ø)
lib/src/fields/dropdown_super_form_field.dart	100.00% <100.00%> (ø)
lib/src/fields/radio_super_form_field.dart	100.00% <100.00%> (ø)
lib/src/fields/slider_super_form_field.dart	100.00% <100.00%> (ø)
lib/src/fields/text_super_form_field.dart	100.00% <100.00%> (ø)
lib/src/super_form.dart	100.00% <100.00%> (ø)
lib/src/super_form_field.dart	100.00% <100.00%> (ø)
... and 3 more

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