added validation for country code in tax settings, closes #5180
fixed a variable overwritten in tax settings
fixed another variable overwritten in tax settings
Merge pull request #5574 from claudiosmweb/fix-tax-settings-save

[2.1] Fix a variable overwritten in tax settings
Merge pull request #5573 from claudiosmweb/5180-tax-validation

Add validation for country code in tax settings
[2.2] Log changes Closes #4926

Added WC_LOG_DIR constant
Added log viewer
Changed default logging directory to 1 up from ABSPATH inside wc-logs
2 filters for drop down functions Closes #5161
Min
When getting grouped products, don't suppress filters

Closes #4661