[BUG] wrong data (subject, event occurence) in rule-generated emails run in batch mode

[oba-reliatec]

Description:
Rules can generate emails in LibreClinica. When running such rules in batch mode, they can contain wrong data, i. e. the wrong subject or event occurrence.

Requirements:
A study with rules, that generate emails.
Enter some subjects (e.g. s1, s2, s3) and create a rule that generates emails if its target meets a certain condition, e. g. item weight in CRF antropometrics is less than 60 kg. Enter one or more subjects with weight < 60 kg (e.g. s1: 70 kg, s2: 45 kg, s3: 59 kg).

Steps to follow:

1. In the Tasks menu select CRFs and click on the view icon (magnifier) that shows the CRF metadata (for CRF antropometrics following the above example).
2. Click "Run All Rules for this CRF" and submit.
3. Review the email(s) sent.

Expected result:
The email should contain the correct subject (e. g. s2 for the subject with 45 kg, and s3 for the subject with 59 kg) and event occurrence.

Actual result:
The emails contain the same subject and event occurrence, which might be right (by chance) or not.

Related (optional):
#340

Screenshots (optional):

Server Setup (optional):

• OS Debian 10
• Application Server Tomcat9
• Java openjdk-14-jdk
• Postgresql 12

Additional context (optional):
If the rule is executed individually it works, the problem only occurs on batch.
This bug is also present in OpenClinica and inherited from there.