Frontend ~ editable text

[andreaj00]

NOTE, Merge first the pull request: #527

New Feature:

Added the possibility to modify the logs that each MIR node sends by modifying the incoming message. (For now, only the JSON leaves are modifiable. )
All the JSON types have been taken care of:

• it's important to notice that once a 'null' field is clicked to modify, it will become a 'string type afterward'.
• For other types, the type will be preserved if the newly modified value is acceptable for that specific type. For example, inserting 'true' into a boolean field will remain a boolean, but using 'tru' will result in it becoming a string field.

Usage Example:

Modifiable incoming log (highlighted by the border line):

Once clicked it becomes editable as a string:

By clicking 'Replace' the modified version will be saved (and we will receive the next log in the 'Incoming Log' section):

If we click simply 'Accept' we will accept the original version of the incoming log (and we will receive the next log in the 'Incoming Log' section):

If we click 'Decline' will just decline and drop the message (even if modified) (and we will receive the next log in the 'Incoming Log' section)

[matejpavlovic]

Finally almost ready to merge this @andreaj00 ! :-)
It just needs to be rebased on top of the visualization branch. There are some conflicts that can probably be trivially resolved (by you, not by me, even though I tried to have a look at it myself).
I'll merge it as soon as the conflicts are resolved.