prevent display of "unexpected EOF" parser errors in diagnostics

[acao]

Current Behavior:

The lsp server shows useless validation errors for empty graphql strings

Expected Behavior:

Ignore newlines and whitespace

Details:

the last release eliminated parse errors that would actually crash the server - these were my mistake, oops!

this fixes another annoying, non-useful parse error that is often seen when authoring a new operation

this should work in most cases, except for cases where there are only comments and no actual graphql types, but it's hard to come up with an efficient pass. this takes care of this bug, when authoring graphql and your cursor is here:

gql`|`

or with newlines:

gql`
|
`

or with whitespace & newlines:

gql`
  |
`

or something as short as:

typ

where op validation doesn't need to kick in yet.

[changeset-bot]

🦋 Changeset detected

Latest commit: b4de923

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

This PR includes changesets to release 1 package

Name	Type
graphql-language-service-server	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[github-actions]

The latest changes of this PR are not available as canary, since there are no linked changesets for this PR.

[codecov]

Codecov Report

Merging #2385 (b4de923) into main (2d91916) will decrease coverage by 0.92%.
The diff coverage is 74.04%.

@@            Coverage Diff             @@
##             main    #2385      +/-   ##
==========================================
- Coverage   65.70%   64.78%   -0.93%     
==========================================
  Files          85       81       -4     
  Lines        5106     5330     +224     
  Branches     1631     1723      +92     
==========================================
+ Hits         3355     3453      +98     
- Misses       1747     1873     +126     
  Partials        4        4              

Impacted Files	Coverage Δ
packages/codemirror-graphql/src/hint.ts	94.73% <ø> (ø)
packages/codemirror-graphql/src/lint.ts	100.00% <ø> (ø)
packages/codemirror-graphql/src/results/mode.ts	47.05% <ø> (ø)
...kages/codemirror-graphql/src/utils/forEachState.ts	100.00% <ø> (ø)
packages/codemirror-graphql/src/utils/hintList.ts	95.65% <ø> (ø)
...ackages/codemirror-graphql/src/utils/info-addon.ts	1.02% <ø> (ø)
...ckages/codemirror-graphql/src/utils/mode-indent.ts	0.00% <0.00%> (ø)
packages/codemirror-graphql/src/variables/hint.ts	89.70% <ø> (ø)
packages/codemirror-graphql/src/variables/mode.ts	79.48% <ø> (ø)
packages/graphiql/src/utility/fillLeafs.ts	5.33% <ø> (ø)
... and 77 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 1bea864...b4de923. Read the comment docs.