Handle escape string for strings containing quotes

[skhugh]

What this PR does / why we need it?

Removed single quotes from escaping.
Escape string for object keys.

Any background context you want to provide?

What are the relevant tickets?

yorkie-team/yorkie-js-sdk#700

Fixes #

Checklist

• Added relevant tests or not required
• Didn't break anything

[7hong13]

I think it also needs to applied to the attributes keys in CrdtText.value:

yorkie-android-sdk/yorkie/src/main/kotlin/dev/yorkie/document/crdt/TextInfo.kt

Line 57 in 99713c1

""""${it.key}":"${escapeString(it.value)}""""

[skhugh]

5f002c9

Thanks for the heads up.
It is done at 5f002c9. Also added test codes for it.

[skhugh]

I think it also needs to applied to the attributes keys in CrdtText.value:

yorkie-android-sdk/yorkie/src/main/kotlin/dev/yorkie/document/crdt/TextInfo.kt

Line 57 in 99713c1

""""${it.key}":"${escapeString(it.value)}""""

Thanks for the heads up. It is done at 5f002c9. Also added test codes for it.