Inject Python string patterns into embedded SQL strings

[winstliu]

Requirements

• Filling out the template is required. Any pull request that does not include enough information to be reviewed in a timely manner may be closed at the maintainers' discretion.
• All new code requires tests to ensure against regressions

Description of the Change

atom/language-sql#70 now uses some begin/end patterns, which messes with language-python's ability to tokenize escaped characters and formatting specifiers in them. To work around that, we now inject those patterns with the highest priority when an embedded SQL string is detected.

Alternate Designs

Don't use begin/end patterns to match parentheses in language-sql.

Benefits

Backslashes in embedded SQL strings should be tokenized correctly again.

Possible Drawbacks

None?

Applicable Issues

Fixes #240

Note: needs specs, though adding specs to cover this may take effort because the existing specs are useless.

[winstliu]

[Arcanemagus]

Is this going to be an issue in other languages that embed SQL like PHP?

[winstliu]

...probably, yeah.