fix(chart): Re allow to use wildcard in curve definition

[lpinsivy]

Pull Request Template

Description

• Re allow to use wildcard in curve definition
• Fix variable name to prevent PHP warning

Fixes #8131

Type of change

• [] Patch fixing an issue (non-breaking change)
• New functionality (non-breaking change)
• Breaking change (patch or feature) that might cause side effects breaking part of the Software
• Updating documentation (missing information, typo...)

Target serie

• 2.8.x
• 18.10.x
• 19.04.x
• 19.10.x
• 20.04.x (master)

How this pull request can be tested ?

1. Edit/create a curve definition
2. Use PRCE in curve name
3. Display a chart that one of the metrics can be validated by the definition
4. Check the curve definition is used (legend name, color of curve, ...)

Checklist

Community contributors & Centreon team

• I followed the coding style guidelines provided by Centreon
• I have commented my code, especially new classes, functions or any legacy code modified. (docblock)
• I have commented my code, especially hard-to-understand areas of the PR.
• I have made corresponding changes to the documentation.
• I have rebased my development branch on the base branch (master, maintenance).

Centreon team only

• I have made sure that the unit tests related to the story are successful.
• I have made sure that unit tests cover 80% of the code written for the story.
• I have made sure that acceptance tests related to the story are successful (local and CI)