Trimming empty string values

[mabar]

Description

Add trimming string values to support error-prone user-given form inputs

• StringValue() - parameter trim=bool, default false
• Rules casting from string should also trim value, when casting is enabled (without any additional option). Specifically BoolValue() castBoolLike, FloatValue() castNumericString, IntValue() castNumericString, NullValue() castEmptyString
• Options dynamic context to change all of above dynamically in runtime. e.g. StringDynamicContext with trim=true would enable all processed StringValue() to trim values. trim=false would disable all. Differentiating between implicit and explicit parameters is probably not needed.

Addition information

cc @mrceperka

Related issues

No response