[Recorder] Fix encode method for special characters - ~

[HarshaNalluru]

@joheredi reached out with a problem where the playback was failing upon rerecording a certain test.

Discussed this with @sadasant who has originally implemented the encoding/decoding parts.
The reason being the generated recording was not replaced as per the replaceable variables provided.
The reason being the secret had ~ character, and encodeRFC3986 method doesn't encode the character.
RFC 3986 standard does not encode the character, but the recordings have that encoded, so adding a new method encodeSpecialCharacters in the recorder to encode ~ character to allow the replacements to happen smoothly.

In case we find such characters in future, they should be added to the list in encodeSpecialCharacters method that is being added in this PR.

[sadasant]

For the record, RFC 3986 says:

Unreserved Characters

Characters that are allowed in a URI but do not have a reserved
purpose are called unreserved. These include uppercase and lowercase
letters, decimal digits, hyphen, period, underscore, and tilde.

unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"

Later it says:

When a URI is dereferenced, the components and subcomponents
significant to the scheme-specific dereferencing process (if any)
must be parsed and separated before the percent-encoded octets within
those components can be safely decoded, as otherwise the data may be
mistaken for component delimiters. The only exception is for
percent-encoded octets corresponding to characters in the unreserved
set, which can be decoded at any time. For example, the octet
corresponding to the tilde ("~") character is often encoded as "%7E"
by older URI processing implementations; the "%7E" can be replaced by
"~" without changing its interpretation.

This specification was added in 2005. JS encoding methods are likely older (but there could be some other explanation of why this is missing that I might not be aware of).

[sadasant]

since the specification says that these are the characters they ignore: "-" / "." / "_" / "~",

let’s make sure we have a test in which we check how bad things get if we have a secret with those other characters 🙌

[deyaaeldeen]

FYI I bumped into the encoded tilde issue in #17732 and I had to replace the client secret manually to get unblocked. I also confirm that I tested this branch and it works great in my case!

[azure-sdk]

API changes have been detected in @azure-rest/purview-catalog. You can review API changes here

[azure-sdk]

API changes have been detected in @azure-rest/core-client. You can review API changes here

API changes

+     binaryContent?: boolean;

[ramya-rao-a]

Am I missing something here? The PR talks about recorder issue, but the files updated include the confidential-ledger, purview and core packages with changes unrelated to the recorder...

[HarshaNalluru]

Testing the fix on Jose's branch.
Moved to draft. :)

[ramya-rao-a]

@joheredi, @HarshaNalluru, what are the next steps here?

[joheredi]

@joheredi, @HarshaNalluru, what are the next steps here?

I believe the new recorder wouldn't run into these issues, so maybe the best plan forward would be to migrate the libraries impacted by this.

[ramya-rao-a]

@HarshaNalluru In that case, I would recommend closing any ongoing PRs for the old recorder