Grammar allows inconsistent condition chaining

[qpanda]

The current version of the expression grammar allows for inconsistent condition chaining:

• 🆗 <condition> and <condition> or <condition> is valid
• 🆗 <condition> or <condition> and <condition> is valid
• 🆖 <condition> and <condition> and <condition> is invalid
• 🆖 <condition> or<condition> or <condition> is invalid
• 🆗 <condition> and <condition> or <condition> and is valid
• 🆗 <condition> and <condition> or <condition> and is valid

The grammar should either allow chaining together any number of conditions or should enforce parenthesis to be used. The inconsistency is a result of operator precedence implemented (or precedes and).