id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,pull_request,body,repo,type,active_lock_reason,performed_via_github_app,reactions,draft,state_reason
978086284,MDExOlB1bGxSZXF1ZXN0NzE4NzM0MTkx,22,Make sure that case-insensitive column names are unique,32016596,open,0,,,1,2021-08-24T13:13:38Z,2021-08-24T13:26:20Z,,FIRST_TIME_CONTRIBUTOR,dogsheep/healthkit-to-sqlite/pulls/22,"This closes #21.

When there are metadata entries with the same case insensitive string, then there is an error when trying to create a new column for that metadata entry in the database table, because a column with that case insensitive name already exists.

```xml
 <Record type=""HKQuantityTypeIdentifierDietaryCholesterol"" sourceName=""MyFitnessPal"" sourceVersion=""35120"" unit=""mg"" creationDate=""2021-07-04 20:55:27 +0200"" startDate=""2021-07-04 20:55:00 +0200"" endDate=""2021-07-04 20:55:00 +0200"" value=""124"">
  <MetadataEntry key=""meal"" value=""Dinner""/>
  <MetadataEntry key=""Meal"" value=""Dinner""/>
 </Record>
```

The code added in this PR checks if a key already exists in a record and if so adds a number at its end. The resulting column names look like the example below then. Interestingly, the column names viewed with Datasette are not case insensitive.

```text
startDate, endDate, value, unit, sourceName, sourceVersion, creationDate, metadata_meal, metadata_Meal_2, metadata_Mahlzeit
```
",197882382,pull,,,"{""url"": ""https://api.github.com/repos/dogsheep/healthkit-to-sqlite/issues/22/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",0,
977128935,MDU6SXNzdWU5NzcxMjg5MzU=,21,Duplicate Column,32016596,open,0,,,1,2021-08-23T15:00:44Z,2021-08-23T17:00:59Z,,NONE,,"Hey, thank you for this repo!

When I try to convert my export, I get a multiple column error. Here is the stack trace:

```sh
(.venv) (base) computer:bodyweight_app user$ healthkit-to-sqlite ./data/Health_export.zip ./data/healthkit.db
Importing from HealthKit  [###############################-----]   87%  00:00:22
Traceback (most recent call last):
  File ""/MyProject/.venv/bin/healthkit-to-sqlite"", line 10, in <module>
    sys.exit(cli())
  File ""/MyProject/.venv/lib/python3.7/site-packages/click/core.py"", line 829, in __call__
    return self.main(*args, **kwargs)
  File ""/MyProject/.venv/lib/python3.7/site-packages/click/core.py"", line 782, in main
    rv = self.invoke(ctx)
  File ""/MyProject/.venv/lib/python3.7/site-packages/click/core.py"", line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File ""/MyProject/.venv/lib/python3.7/site-packages/click/core.py"", line 610, in invoke
    return callback(*args, **kwargs)
  File ""/MyProject/.venv/lib/python3.7/site-packages/healthkit_to_sqlite/cli.py"", line 57, in cli
    convert_xml_to_sqlite(fp, db, progress_callback=bar.update, zipfile=zf)
  File ""/MyProject/.venv/lib/python3.7/site-packages/healthkit_to_sqlite/utils.py"", line 41, in convert_xml_to_sqlite
    write_records(records, db)
  File ""/MyProject/.venv/lib/python3.7/site-packages/healthkit_to_sqlite/utils.py"", line 146, in write_records
    batch_size=50,
  File ""/MyProject/.venv/lib/python3.7/site-packages/sqlite_utils/db.py"", line 2579, in insert_all
    extracts=extracts,
  File ""/MyProject/.venv/lib/python3.7/site-packages/sqlite_utils/db.py"", line 1246, in create
    extracts=extracts,
  File ""/MyProject/.venv/lib/python3.7/site-packages/sqlite_utils/db.py"", line 767, in create_table
    self.execute(sql)
  File ""/MyProject/.venv/lib/python3.7/site-packages/sqlite_utils/db.py"", line 421, in execute
    return self.conn.execute(sql)
sqlite3.OperationalError: duplicate column name: metadata_Meal
```",197882382,issue,,,"{""url"": ""https://api.github.com/repos/dogsheep/healthkit-to-sqlite/issues/21/reactions"", ""total_count"": 5, ""+1"": 5, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,