Shutdown inactive tenants

#### Describe the bug

We currently do not shut down tenants after they stop ingested or if they only query. This can be seen by errors like this;

```
level=error caller=phlaredb.go:157 ts=2023-06-15T09:34:35.028355532Z tenant=test-f msg="flushing head block failed" err="rename data/test-f/head/01H2Z6EDDK79F47B0YS41QQV42 data/test-f/local/01H2Z6EDDK79F47B0YS41QQV42: no such file or directory"
level=error caller=phlaredb.go:157 ts=2023-06-15T09:35:33.581804511Z tenant=test-e msg="flushing head block failed" err="rename data/test-e/head/01H2Z6G6KDX0PP7SK6A6K0PHSX data/test-e/local/01H2Z6G6KDX0PP7SK6A6K0PHSX: no such file or directory"
level=error caller=phlaredb.go:157 ts=2023-06-15T09:35:35.029651043Z tenant=test-f msg="flushing head block failed" err="rename data/test-f/head/01H2Z6G80KSC8RPGJJRFXXNMPW data/test-f/local/01H2Z6G80KSC8RPGJJRFXXNMPW: no such file or directory"
level=error caller=phlaredb.go:157 ts=2023-06-15T09:36:33.582905922Z tenant=test-e msg="flushing head block failed" err="rename data/test-e/head/01H2Z6J16DYPWGZ2T28HFSSWF3 data/test-e/local/01H2Z6J16DYPWGZ2T28HFSSWF3: no such file or directory"
level=error caller=phlaredb.go:157 ts=2023-06-15T09:36:35.029903716Z tenant=test-f msg="flushing head block failed" err="rename data/test-f/head/01H2Z6J2KNACMVXWJQJF2RW0FW data/test-f/local/01H2Z6J2KNACMVXWJQJF2RW0FW: no such file or directory"
level=error caller=phlaredb.go:157 ts=2023-06-15T09:37:33.583742876Z tenant=test-e msg="flushing head block failed" err="rename data/test-e/head/01H2Z6KVSE06TC0XDZ21RMQQ9T data/test-e/local/01H2Z6KVSE06TC0XDZ21RMQQ9T: no such file or directory"
level=error caller=phlaredb.go:157 ts=2023-06-15T09:37:35.03101748Z tenant=test-f msg="flushing head block failed" err="rename data/test-f/head/01H2Z6KX6N17XH6CWH2BD300NF data/test-f/local/01H2Z6KX6N17XH6CWH2BD300NF: no such file or directory"
level=error caller=phlaredb.go:157 ts=2023-06-15T09:38:33.584307462Z tenant=test-e msg="flushing head block failed" err="rename data/test-e/head/01H2Z6NPCEHQVC79TPXK989D5J data/test-e/local/01H2Z6NPCEHQVC79TPXK989D5J: no such file or directory"
level=error caller=phlaredb.go:157 ts=2023-06-15T09:38:35.032439564Z tenant=test-f msg="flushing head block failed" err="rename data/test-f/head/01H2Z6NQSPG2S5SJQ918A45TFH data/test-f/local/01H2Z6NQSPG2S5SJQ918A45TFH: no such file or directory"
level=error caller=phlaredb.go:157 ts=2023-06-15T09:39:33.585038255Z tenant=test-e msg="flushing head block failed" err="rename data/test-e/head/01H2Z6QGZFZYW1A4MXGWJT7DVT data/test-e/local/01H2Z6QGZFZYW1A4MXGWJT7DVT: no such file or directory"
level=error caller=phlaredb.go:157 ts=2023-06-15T09:39:35.032765104Z tenant=test-f msg="flushing head block failed" err="rename data/test-f/head/01H2Z6QJCQ3STT2E440G9REC4F data/test-f/local/01H2Z6QJCQ3STT2E440G9REC4F: no such file or directory"
level=error caller=phlaredb.go:157 ts=2023-06-15T09:40:33.585486326Z tenant=test-e msg="flushing head block failed" err="rename data/test-e/head/01H2Z6SBJGZ2X0Q2S304WMFAF4 data/test-e/local/01H2Z6SBJGZ2X0Q2S304WMFAF4: no such file or directory"
level=error caller=phlaredb.go:157 ts=2023-06-15T09:40:35.032895443Z tenant=test-f msg="flushing head block failed" err="rename data/test-f/head/01H2Z6SCZRW16FT3TJWRC8NF77 data/test-f/local/01H2Z6SCZRW16FT3TJWRC8NF77: no such file or directory"
level=error caller=phlaredb.go:157 ts=2023-06-15T09:40:36.320883206Z tenant=test-x msg="flushing head block failed" err="rename data/test-x/head/01H2Z6SE808RQNXEJ8KQB28KAN data/test-x/local/01H2Z6SE808RQNXEJ8KQB28KAN: no such file or directory"
level=error caller=phlaredb.go:157 ts=2023-06-15T09:40:46.174610745Z tenant=test-xyz msg="flushing head block failed" err="rename data/test-xyz/head/01H2Z6SQVXGF1RNXSHD2Q8J7KS data/test-xyz/local/01H2Z6SQVXGF1RNXSHD2Q8J7KS: no such file or directory"
```

#### To Reproduce

* Variant: read path
* Query a new and otherwise unused tenant `xyz`
* After `--phlaredb.max-block-duration` we will try to flush the block which will result in the error

* Variant: write path
* Ingest a profile into a tenant `abc`
* After two `--phlaredb.max-block-duration` we will try to flush an empty block which will result in the error

#### Proposed changes

* Do not create a Phlare DB for queries on the read path (instead return empty early) that have no head block or local blocks
* Return the fact that no block was written and prevent the error from being locked