build!: update rxjs to 7

[rars]

BREAKING CHANGE: imports to rxjs/operators removed, depends on 7

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• [ x] The commit message follows our guidelines: CONTRIBUTING.md#commit
• [ x] Tests for the changes have been added (for bug fixes / features)
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PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ x] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Other... Please describe:

What is the current behavior?

Issue Number: N/A

What is the new behavior?

Does this PR introduce a breaking change?

[x] Yes
[ ] No

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[godind]

Bump! I use v7 also