IBX-84: Added REST eZ Commerce for 3.3

[Steveb-p]

Question	Answer
JIRA issue	IBX-84
Type	feature
Target Ibexa version	v3.3.3
BC breaks	no
Doc needed	no (already provided)

Adds ezsystems/ezcommerce-rest as a dependency.

Checklist:

• Provided PR description.
• Tested the solution manually.
• Checked that target branch is set correctly.
• Asked for a review (ping @ibexa/engineering).

[bogusez]

I've found an issue (status code 500) for endpoint with updating / adding product to the basket: /api/ezp/v2/commerce/basket/7/line

To resolve the problem we have to change payload data from:

{ "BasketLinesData": [ { "basketLineId": 5, "lineNumber": 1, "sku": "001", "quantity": "2", "isVariant": "0", "variantCode": "" } ] }

to

{ "BasketLinesData": [ { "sku": "001", "quantity": "2", "isVariant": "0", "variantCode": "" } ] }

Except this, we have also change header Content-Type data to: application/vnd.ez.api.BasketLineData+json

[adamwojs]

@Steveb-p Could you please merge up changes?

[Steveb-p]

Merging up postponed for a second, ezcommerce-rest needs a branch for 4.0 version.

Merged up in 1106fa7.