Closes [BR-395](https://bonitasoft.atlassian.net/browse/BR-395)
Closes [BR-396](https://bonitasoft.atlassian.net/browse/BR-396)

Relates to [BR-346](https://bonitasoft.atlassian.net/browse/BR-346)

Closes [BS-19473](https://bonitasoft.atlassian.net/browse/BS-19473)
Closes [BR-375](https://bonitasoft.atlassian.net/browse/BR-375)

Co-authored-by: Baptiste Mesta <baptiste.mesta@gmail.com>

- it seems that the version 7.9.4 was removed (by mistake ?) when adding version 7.10.0
Fortunately the step is not doing anything but customers cannot choose 7.9.4 when migrating with migration tool 2.46.0

There was an issue when nodes of gateways were not in the right order.
It's the same problem as with the end events.
The XSL didn't reorder the gateway elements, and so, if they were not in the right order when the step was played, it raised an exception when validating with the new XSD.

Change the XSL transformation to force the order of elements on the gateway.

Closes [BR-140](https://bonitasoft.atlassian.net/browse/BR-140)
Closes [BS-19354](https://bonitasoft.atlassian.net/browse/BS-19354)
Closes [BS-19364](https://bonitasoft.atlassian.net/browse/BS-19364)

The premigration warning were not working when executing it on a version < 7.1.0
Change the check to verify in that case page_mapping url adapters

Closes [BS-19363](https://bonitasoft.atlassian.net/browse/BS-19363)

In some case it was possible to have 2 dependencies, one with slash and one
without slash but having the same name.

In that case, remove the previous dependency (the one without the slash)
because the one with the slash should be the last added dependency.

Closes [BR-285](https://bonitasoft.atlassian.net/browse/BR-285)
Closes [BS-18436](https://bonitasoft.atlassian.net/browse/BS-18436)

Migrate idx_message_instance on mysql only, by removing the column correlation3. Needed for compatibility with UTF8MB4.

Closes [BR-257](https://bonitasoft.atlassian.net/browse/BR-257)

Closes [BR-237](https://bonitasoft.atlassian.net/browse/BR-237)

check if exception is a constraint violation exception to log "data already migrated" and if not stop the migration.

Closes [BR-240](https://bonitasoft.atlassian.net/browse/BR-240)

Relates to [BR-237](https://bonitasoft.atlassian.net/browse/BR-237)

This live-migration distrib should be launched after a migration > 7.7.0

Closes [BR-238](https://bonitasoft.atlassian.net/browse/BR-238)

And display warning at end of migration run.

Closes [BR-236](https://bonitasoft.atlassian.net/browse/BR-236)

SNAPSHOT was missing

These tests are time consuming (a slave is required for more than 1.5h to
run tests on Oracle db), almost never fail for a regression or new failure
(but false positive occurs more frequently)

Modifications introduced
  - PR build changes
    - do not run all migration tests by default by rather last migration step
    - run db test only if all migration tests will be ran
    - add a way to skip integration tests
  - Slack: use the new plugin syntax (do not use groovy json construct)
  - Introduce Github PR Template

Verify that the version of Oracle is >= 12.2
If it's not, block the migration because it would fail (see bug BS-19380)

Relates to [BS-19380](https://bonitasoft.atlassian.net/browse/BS-19380)

Closes [BR-240](https://bonitasoft.atlassian.net/browse/BR-240)

This reverts commit a7cb99eb33b27fbefc0de0fbb05042203320f942.

Closes [BR-110](https://bonitasoft.atlassian.net/browse/BR-110)

Theses messages were not clear and caused fear among customers

Closes [BS-19385](https://bonitasoft.atlassian.net/browse/BS-19385)