Add RSA encryption function to templates

[LinuxSuRen]

Related to #501

Adds the rasEncryptWithPublicKey function to the template rendering functionalities and includes unit tests for the new function.

• New Functionality: Implements the rasEncryptWithPublicKey function in pkg/render/template.go, allowing users to encrypt content with a public key directly within templates. This function takes two string arguments (content and key), performs RSA encryption, and returns the encrypted content in base64 encoded format.
• Error Handling: Adds error handling for key parsing and encryption processes within the rasEncryptWithPublicKey function to ensure robustness.
• Unit Tests: Extends pkg/render/template_test.go with tests for the rasEncryptWithPublicKey function, verifying its behavior with both valid and invalid keys, and ensuring the encryption process works as expected.

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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[codacy-production]

Coverage summary from Codacy

See diff coverage on Codacy

Coverage variation	Diff coverage
✅ -0.02%	✅ 60.00%

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (b7926da)	15067	6496	43.11%
Head commit (14443d2)	15086 (+19)	6501 (+5)	43.09% (-0.02%)

Coverage variation is the difference between the coverage for the head and common ancestor commits of the pull request branch: <coverage of head commit> - <coverage of common ancestor commit>

Diff coverage details

	Coverable lines	Covered lines	Diff coverage
Pull request (#502)	20	12	60.00%

Diff coverage is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: <covered lines added or modified>/<coverable lines added or modified> * 100%

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[github-actions]

There are 1 test cases, failed count 0:

Name	Average	Max	Min	Count	Error
	9.383516ms	11.376308ms	8.331835ms	3	0

Reported by api-testing.