Parsing and rendering error modes

[sebastienros]

c.f. https://github.com/Shopify/liquid?tab=readme-ov-file#error-modes

Parsing should be lax and not fail by default. Using the strict mode the parser should fail. With the warn mode the parse won't fail but still report errors.

FOr rendering the strict_variables and strict_filters will throw an exception if any unknown variables or filters are used.

[sebastienros]

The strict parsing probably involves duplicating most parsers based on this setting. Like "Expression" and "ExpressionStrict". This is what Shopify does.

[sebastienros]

Note that Shopify has too levels: Strict and Strict2 (previously "Rigid") ;)