Fix overly strict lifetime requirements for deserialization helpers

[phil-opp]

And other improvements:

• Don't deny clippy lints to avoid breakage when new lints are created
• Add Key bound on Keyed::K so that we don't need to specify it on every usage

[phil-opp]

Happy to split this up into separate PRs if you prefer.

[codecov-commenter]

Codecov Report

Patch coverage: 66.66% and project coverage change: -0.09 :warning:

Comparison is base (3b4f224) 70.44% compared to head (48890c5) 70.36%.

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Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #291 +/- ## ========================================== - Coverage 70.44% 70.36% -0.09% ========================================== Files 111 111 Lines 20278 20261 -17 ========================================== - Hits 14285 14256 -29 - Misses 5993 6005 +12 ``` | [Impacted Files](https://app.codecov.io/gh/jhelovuo/RustDDS/pull/291?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None) | Coverage Δ | | |---|---|---| | [src/dds/key.rs](https://app.codecov.io/gh/jhelovuo/RustDDS/pull/291?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None#diff-c3JjL2Rkcy9rZXkucnM=) | `64.47% <ø> (ø)` | | | [src/dds/pubsub.rs](https://app.codecov.io/gh/jhelovuo/RustDDS/pull/291?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None#diff-c3JjL2Rkcy9wdWJzdWIucnM=) | `85.95% <ø> (-0.10%)` | :arrow_down: | | [src/dds/with\_key/datareader.rs](https://app.codecov.io/gh/jhelovuo/RustDDS/pull/291?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None#diff-c3JjL2Rkcy93aXRoX2tleS9kYXRhcmVhZGVyLnJz) | `84.41% <ø> (ø)` | | | [src/dds/with\_key/datasample.rs](https://app.codecov.io/gh/jhelovuo/RustDDS/pull/291?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None#diff-c3JjL2Rkcy93aXRoX2tleS9kYXRhc2FtcGxlLnJz) | `40.35% <0.00%> (+2.01%)` | :arrow_up: | | [src/dds/with\_key/datasample\_cache.rs](https://app.codecov.io/gh/jhelovuo/RustDDS/pull/291?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None#diff-c3JjL2Rkcy93aXRoX2tleS9kYXRhc2FtcGxlX2NhY2hlLnJz) | `81.34% <ø> (ø)` | | | [src/dds/with\_key/datawriter.rs](https://app.codecov.io/gh/jhelovuo/RustDDS/pull/291?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None#diff-c3JjL2Rkcy93aXRoX2tleS9kYXRhd3JpdGVyLnJz) | `60.18% <ø> (ø)` | | | [src/dds/with\_key/simpledatareader.rs](https://app.codecov.io/gh/jhelovuo/RustDDS/pull/291?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None#diff-c3JjL2Rkcy93aXRoX2tleS9zaW1wbGVkYXRhcmVhZGVyLnJz) | `54.57% <ø> (ø)` | | | [src/lib.rs](https://app.codecov.io/gh/jhelovuo/RustDDS/pull/291?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None#diff-c3JjL2xpYi5ycw==) | `100.00% <ø> (ø)` | | | [src/ros2/ros\_node.rs](https://app.codecov.io/gh/jhelovuo/RustDDS/pull/291?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None#diff-c3JjL3JvczIvcm9zX25vZGUucnM=) | `50.27% <ø> (+0.27%)` | :arrow_up: | | [src/test/test\_properties.rs](https://app.codecov.io/gh/jhelovuo/RustDDS/pull/291?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None#diff-c3JjL3Rlc3QvdGVzdF9wcm9wZXJ0aWVzLnJz) | `100.00% <ø> (ø)` | | | ... and [1 more](https://app.codecov.io/gh/jhelovuo/RustDDS/pull/291?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None) | | ... and [4 files with indirect coverage changes](https://app.codecov.io/gh/jhelovuo/RustDDS/pull/291/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None)

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[jhelovuo]

Thanks. This is much appreciated. It seems that specifying trait bounds on an associated type works now better than it did ~3 years ago.

[ohuopio]

Yes, these seem to be good improvements. Thank you!