feat(frontend): allow to set that db history tables were updated (zabbix 5.0+)

[ghormoon]

PR progress checklist (to be filled in by reviewers)

• [ ] Changes to documentation are appropriate (or tick if not required)
• [ ] Changes to tests are appropriate (or tick if not required)
• [ ] Reviews completed

---

What type of PR is this?

Primary type

• [x] [feat] A new feature

Secondary type

• [x] [docs] Documentation changes

Does this PR introduce a BREAKING CHANGE?

No.

Related issues and/or pull requests

Describe the changes you're proposing

Zabbix 5.0 will complain in froentend with "Database history tables upgraded | No" unless a variable is set ij web connfig file. Unfortunately upgrading the tables is not enough, it needs to be told in config too. This should be done in pillar when upgrading.

Pillar / config required to test the proposed changes

zabbix:
  lookup:
    version_repo: 5.4
    frontend:
      historyupgraded: true

Debug log showing how the proposed changes work

          ID: /etc/zabbix/web/zabbix.conf.php
    Function: file.managed
      Result: True
     Comment: File /etc/zabbix/web/zabbix.conf.php updated
     Started: 14:52:25.967616
    Duration: 224.967 ms
     Changes:   
              ----------
              diff:
                  --- 
                  +++ 
                  @@ -16,4 +16,5 @@
                   $ZBX_SERVER_NAME             = 'Zabbix installed with SaltStack';

                   $IMAGE_FORMAT_DEFAULT        = IMAGE_FORMAT_PNG;
                  +$DB['DOUBLE_IEEE754'] = 'true';
                   ?>

Documentation checklist

• [ ] Updated the README (e.g. Available states).
• [x] Updated pillar.example.

Testing checklist

• [ ] Included in Kitchen (i.e. under state_top).
• [ ] Covered by new/existing tests (e.g. InSpec, Serverspec, etc.).
• [ ] Updated the relevant test pillar.

Additional context