[2.8.9] Special chars in perfdata breaks graph legend

[itsul]

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BUG REPORT INFORMATION

Centreon Web version: 2.8.9

Centreon Engine version: 1.7.2

Centreon Broker version: 3.0.7

OS: CES 3.4/CentOS 6.9

**Additional environment details (AWS, VirtualBox, physical, etc.): VMWare,KVM,Physical

Steps to reproduce the issue:

1. Create a check command with a backslash or percent char in perfdata.
   For example |'test%'=0;;;; or |'\test'=0;;;;.
   Unfortunately that's common for various NSClient++ checks like physikal memory or disk space.
2. Go to monitorig and look at the perfdata hover

Describe the results you received:
The metric legend in the perfdata hover is missing and the design looks broken.
In the graph details the legend is missing, too.

Describe the results you expected:
The metric legend should be displayed correctly.

[mwielander]

here an example

[mwielander]

here perfdata example

[kduret]

Fix blank spaces in metric name : 6ea9035

[lpinsivy]

linked to #5554 and should be fix by #5579