fix: Increase EXI limit to 7500 (CPISU-1276)

[tnn]

Description

What?

Increase the EXI payload limit for Get15118EVCertificate from 5600 to 7500 characters.

Increased the timeout when waiting for async completion of responses during tests from 1 sec to 5 sec, due to GHA build failures.

Why?

Allow a 4-chain certificate chain to be included and allows vehicles to signal support for multiple OEM / MO roots when requesting Contract Certificates.
Required by Hubject Plug&Charge: https://support.hubject.com/hc/en-us/articles/9174328536221-3-6-Requirements-for-CPMS

2.2 Deviation from OCPP Message Get15118EVCertificate (processual)

Context

As part of implementing support for Plug&Charge. This is categorized as an bug, but we have not yet run into this problem in production.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
  • add further detail on which functionality would break and how to migrate

[github-actions]

Test Results

52 tests   52 ✅  3s ⏱️
13 suites   0 💤
13 files     0 ❌

Results for commit af053e8.

♻️ This comment has been updated with latest results.

[github-actions]

Code Coverage

Overall Project	NaN% NaN%	🍏

There is no coverage information present for the Files changed