Problem description: Currently, it is allowed to save entities with tag names and values that contain spaces.
There are several places in frontend, where during filtering by tag name or value with operator "Contains" trailing and leading spaces are being trimmed from the specified value, even though the user might have intentionally put a trailing/leading space there to make sure that the specified value is not the only word in the corresponding tag.
List of such spaces in frontend:

• SLA configuration => Service tags
• Service => Problem tags
• Widgets configuration
• Data collection => Host/Template Web scenarios (Tags filter)
• Data collection => Maintenance => Maintenance configuration form
• Data collection => Event correlation/Event processing => CEP rule/Event corelation conditions
• Alerts => Actions => Action conditions

There are also several spaces where trailing and leading spaces are not trimmed (which is expected), for example in tag filters in:

• Monitoring => Problems
• Monitoring => Latest data
• Reports => Top 100 triggers,
• Monitoring => Maps: Map elements => problem tags
• Data collection => Hosts (Tags filter)
• Data collection => Host/Template items (Tags filter)
• Data collection => Host/Template triggers (Tags filter)

Steps to reproduce:

1. Create 2 web scenarios
   1. One with tag: "return => only me"
   2. One with tag: "return => not_me"
2. Open the list of Web scenarios for this host and attempt to filter them using the following Tag filter:
   • tag => return
   • operator => Contains
   • value => " me"

Result: the leading space was trimmed, and both web scenarios are returned in the list
Expected: the leading space should not be trimmed and only the 1st web scenario should be returned.