[redcap] Add REDCap automatic session creation

[MaximeBICMTL]

First two commits are #9839.

Successfully tested in C-BIG dev (in a backported version).

[MaximeBICMTL]

The CI errors are on main and not from this PR. Fixed the remaining TODO and successfully tested on C-BIG dev. Ready for review.

I only added the last commit and rebased on main since last review. PR history is just messy because of the rebases, the commit history is still clean.

[regisoc]

One comment, but LGTM if that was already tested on C-BIG dev.
Most of the name changes are coming from the previous PR.

[regisoc]

@ridz1208 let me know, but if already tested on C-BIG, LGTM.
I am interested to port it to IBIS too for more tests, if possible in few weeks.

[ridz1208]

@regisoc functional on CBIG!

[MaximeBICMTL]

Blocked by the following:

• Merge [redcap] REDCap module improvements #9839
• Make the timestamp field optional and add fallback options.
• Separate session creation from next step registration.

EDIT: Last two points are done, see last two commits.

[regisoc]

I do not think there is any major issues on the few last additions, and it was already reviewed few days ago. Last additions are focused the points mentioned above, notably:

• Make the timestamp field optional and add fallback options.
• Separate session creation from next step registration.

LGTM as it was already tested on CBIG.

One important note that was part of discussions on slack: the optional _timestamp field should always appear when importing data from REDCap instrument because it is embedded in the survey metadata parameter exportSurveyFields of the payload.
As this field is always present (correct timestamp or empty string) on projects such as HBCD and IBIS, but was mentioned to be absent on some others (CBIG/MPN?), a new PR is required to control that this field is indeed present in imported REDCap record data.

[regisoc]

Note here: that is the LORIS server datetime, not the REDCap one (timezone might be different).