fix: escape double quotes in Mermaid ER diagram relation definitions

[k1LoW]

fix: #790

[github-actions]

Code Metrics Report

	main (a08ee94)	#795 (1d35d90)	+/-
Coverage	54.1%	52.6%	-1.5%
Code to Test Ratio	1:0.5	1:0.5	0.0
Test Execution Time	4m59s	4m48s	-11s

Details

  |                     | main (a08ee94) | #795 (1d35d90) |  +/-  |
  |---------------------|----------------|----------------|-------|
- | Coverage            |          54.1% |          52.6% | -1.5% |
  |   Files             |             54 |             54 |     0 |
  |   Lines             |           5292 |           5292 |     0 |
- |   Covered           |           2863 |           2784 |   -79 |
  | Code to Test Ratio  |          1:0.5 |          1:0.5 |   0.0 |
  |   Code              |          11407 |          11407 |     0 |
  |   Test              |           5849 |           5849 |     0 |
+ | Test Execution Time |          4m59s |          4m48s |  -11s |

Code coverage of files in pull request scope (50.4% → 27.4%)

Files	Coverage	+/-	Status
datasource/datasource.go	49.1%	-0.6%	affected
datasource/gcp.go	10.6%	-27.7%	affected
drivers/bq/bq.go	0.0%	-91.3%	affected
testutil/schema.go	0.0%	0.0%	modified

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Reported by octocov