🪲 Variable access before definition error raised incorrectly

[boryanagoncharenko]

Describe the bug
In some cases a command could consider an argument either as a variable, if such is defined, or a literal string. If a variable is defined and if is accessed before its definition, an error is raised. The access-before-definition check uses only line numbers. As a result, the following snippet produces an error while it should not.

Paste the Hedy code & level
Level 12:

define turn
    if x is pressed
        print 'good'
    else
        print 'bad'

print 'Start'
call turn
x is 1 + 1
print x
print 'End'

The access-before-definition check should take into account that functions use another scope.

[boryanagoncharenko]

This issue is tightly-coupled to #5749