Bufferisation in join rule

[innovimax-jim]

Some joining cases require to bufferize line(s) to complete the operation.
Two test cases have been added for that (18 & 22) but they have "locked" status so they are not processed for the moment.

Example 1 :

File 1 | File 2__ | Result
a A 1 | a AA 10 | a A 1 AA 10
b B 1 | b BB 10 | b B 1 BB 10
b B 2 | c CC 10 | b B 2 BB 10
b B 3 | c CC 11 | b B 3 BB 10
c C 1 | ________ | c C 1 CC 10
_____ | ________ | c C 1 CC 11

Example 2 :

File 1 | File 2__ | Result
a A 1 | b BB 10 | b B 1 BB 10
b B 1 | b BB 11 | b B 1 BB 11
b B 2 | b BB 13 | b B 1 BB 12
_____ | c CC 10 | b B 2 BB 10
_____ | ________ | b B 2 BB 11
_____ | ________ | b B 2 BB 12

Example 3 :

File 1 | File 2__ | File 3_____ | Result
a A 1 | a AA 10 | a AAA 100 | a A 1 a AA 10 AAA 100
_____ | a AA 11 | a AAA 101 | a A 1 a AA 10 AAA 101
_____ | a AA 12 | ___________ | a A 1 a AA 11 AAA 100
_____ | ________ | ___________ | a A 1 a AA 11 AAA 101
_____ | ________ | ___________ | a A 1 a AA 12 AAA 100
_____ | ________ | ___________ | a A 1 a AA 12 AAA 101