fix(typescript-urql-graphcache): improve typing

[dargmuesli]

Description

Linting typescript-urql-graphcache's output file showed some room for improvement, so this PR resolves a duplicate import source and improves typing for "empty object".

Related # (issue)

#1109
#445

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as
  expected)
• This change requires a documentation update

Screenshots/Sandbox (if appropriate/relevant):

n/a

How Has This Been Tested?

• existing test snapshots have been updated

Checklist:

• I have followed the
  CONTRIBUTING doc and the
  style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

Further comments

n/a

[changeset-bot]

🦋 Changeset detected

Latest commit: 30ee6e8

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@graphql-codegen/typescript-urql-graphcache	Patch

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[dargmuesli]

let me kindly cc last editors of the changed line @beerose and @JoviDeCroock for review if time allows