fix memory leaks in map and bitmap

[Kellesi]

Fix memory leaks in kf::map
Task: https://jira.dev.local/jira/browse/KF-20
Also faced to a little memory leak in kf::Bitmap and fixed it

[SergiusTheBest]

Please, split it into 2 separate PRs and add tests for them.

[Kellesi]

This issue was detected by driver verifier. Should I create my own test for memory leaks?

[SergiusTheBest]

This issue was detected by driver verifier. Should I create my own test for memory leaks?

@Kellesi If existing tests trigger memory leak then there is no need in creating another test.

[SergiusTheBest]

Please, split it into 2 separate PRs and add tests for them.

@Kellesi What about this?

[Kellesi]

@SergiusTheBest
Memory leaks are already triggered by existing tests and detected by Driver Verifier, so no additional test is needed to trigger it.
Also, if I split the map and bitmap fix into 2 PRs, then the bitmap PR would contain just one line, since memory leak occurs in only one case. So if it is necessary due to any PR standards, could you please share them with me? Because here it seems a bit redundant for me.

[SergiusTheBest]

@Kellesi Mainly it's because one fix is good and can be merger right away and be used by other guys. And another fix requires further discussion. But we can do it later. They are both good enough to be merged. Thank you for the fix! 💪