EVM-680 Dial queue issues fixes

[igorcrevar]

Description

There are multiple small bugs inside dial queue that need to be addressed
For example:

• after deleting task from the queue, corresponding map is not updated, only binary heap is
• if task is added to queue, there is no check that same task is already on the queue
• some other small issues
• remove unnecessary network server subscriptions, simplify code

Slots will be added through separated pr

Changes include

• Bugfix (non-breaking change that solves an issue)
• Hotfix (change that solves an urgent issue, and requires immediate attention)
• New feature (non-breaking change that adds functionality)
• Breaking change (change that is not backwards-compatible and/or changes current functionality)

Breaking changes

Please complete this section if any breaking changes have been made, otherwise delete it

Checklist

• I have assigned this PR to myself
• I have added at least 1 reviewer
• I have added the relevant labels
• I have updated the official documentation
• I have added sufficient documentation in code

Testing

• I have tested this code with the official test suite
• I have tested this code manually

Manual tests

Please complete this section if you ran manual tests for this functionality, otherwise delete it

Documentation update

Please link the documentation update PR in this section if it's present, otherwise delete it

Additional comments

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