Use twosides and threesides

[pjeanmarie]

Please check if the PR fulfills these requirements

• [ ] The commit message follows our guidelines
• [ ] Tests for the changes have been added (for bug fixes / features)
• [ ] Docs have been added / updated (for bug fixes / features)

Does this PR already have an issue describing the problem?

Fixes #908

What kind of change does this PR introduce?

feature

What is the current behavior?

Rao has its enum Side with values LEFT/RIGHT and a conversion method to take equivalent core (iidm) TwoSides ONE/TWO

What is the new behavior (if this is a feature change)?

Rao will use core (iidm) enum TwoSides (values ONE/TWO)

Does this PR introduce a breaking change or deprecate an API?

• [x] Yes
• [ ] No

If yes, please check if the following requirements are fulfilled

• [x] The Breaking Change or Deprecated label has been added
• [ ] The migration steps are described in the following section

What changes might users need to make in their application due to this PR? (migration steps)

Replace use of Side.LEFT by core TwoSides.ONE and Side.RIGHT by core TwoSides.TWO. Crac json is now "side": 1 instead of "side": "left" or "side": 2 instead of "side": "right". Rao result json is now "side1" instead of "leftSide" or "side2" instead of "rightSide". Crac creation parameters enum MonitoredLineSide has change in names: MONITOR_LINES_ON_LEFT/RIGHT_SIDE is now MONITOR_LINES_ON_ONE/TWO_SIDE.

Other information:

[pjeanmarie]

Question: CnecId/modifiedCnecId, ONE TWO or LEFT RIGHT?

[pjeanmarie]

Question: CnecId/modifiedCnecId, ONE TWO or LEFT RIGHT?

replaced