Standardize Exception messages

[omry]

There are some common information thas is applicable to most exceptions:

1. what is the node this happened on.

2. what is the key (if relevent)

3. what is the value (if relevant)

4. what is the full path of the key
   etc.

5. refactor things such that all exceptions are going through the same formatting function.

6. add tests for exception messages.