Use of hard-coded charset string in error messages

[ishantiw]

Description

Several error messages in the interoperability module and its unit tests hard-code the character set for a valid chain name, instead of using the validNameCharset constant. Below are some identified instances.

https://github.com/LiskHQ/lisk-sdk/blob/89e7504ef5eb6183aefe576a93be3d6052e56038/framework/src/modules/interoperability/mainchain/commands/register_sidechain.ts#L85

https://github.com/LiskHQ/lisk-sdk/blob/89e7504ef5eb6183aefe576a93be3d6052e56038/framework/src/modules/interoperability/mainchain/endpoint.ts#L75

https://github.com/LiskHQ/lisk-sdk/blob/89e7504ef5eb6183aefe576a93be3d6052e56038/framework/src/modules/interoperability/sidechain/commands/register_mainchain.ts#L105

https://github.com/LiskHQ/lisk-sdk/blob/89e7504ef5eb6183aefe576a93be3d6052e56038/framework/test/unit/modules/interoperability/mainchain/commands/register_sidechain.spec.ts#L205

https://github.com/LiskHQ/lisk-sdk/blob/89e7504ef5eb6183aefe576a93be3d6052e56038/framework/test/unit/modules/interoperability/mainchain/endpoint.spec.ts#L89

https://github.com/LiskHQ/lisk-sdk/blob/89e7504ef5eb6183aefe576a93be3d6052e56038/framework/test/unit/modules/interoperability/sidechain/commands/register_mainchain.spec.ts#L196

Which version(s) does this affect? (Environment, OS, etc...)

v6.0.0-beta.1

[sitetester]

The Charset part could cause confusion. As usually, when we say Character set. It means encoding system.
Alternative name could be validNameChars.